摘要:
An imaging lens SL mounted in a digital single lens reflex camera 1 is composed of, in order from an object side, a first lens group G1 having negative refractive power, a second lens group G2 having positive refractive power, and a third lens group G3 having positive refractive power, wherein upon focusing on a near-distance object point from an infinite-distance object point, at least one of the first lens group G1 and the second lens group G2 is moved so as to change a distance between the first lens group G1 and the second lens group G2, and the imaging lens satisfies a given conditional expression, thereby providing a downsized imaging lens suited to an imaging apparatus such as a single lens reflex camera, having a less of change in overall length and optimal to driving an intra-lens-barrel motor.
摘要:
The present invention has, in order from an object, a first lens group (G1) having positive refractive power; a second lens group (G2) having negative refractive power; a third lens group (G3) having positive refractive power; and a fourth lens group (G4) having positive refractive power, wherein zooming is performed by changing an air gap between the lens groups, the fourth lens group (G4) includes, in order from the object, a lens component (La) having positive or negative refractive power, a positive lens component (Lb), and a positive lens component (Lc) having a convex surface facing the object, and the following conditional expression is satisfied: 0.00
摘要:
A zoom lens system ZL installed in an electronic still camera 1 and the like comprising, in order from an object side: a first lens group G1 having negative refractive power; and a second lens group G2 having positive refractive power; the second lens group including at least two cemented lenses each of which includes a positive lens disposed to the object side and a negative lens disposed to an image side, a distance between the first lens group and the second lens group varying upon zooming from a wide-angle end state to a telephoto end state, thereby providing a zoom lens system having excellent optical performance, an optical apparatus equipped with the zoom lens system, and a method for manufacturing the zoom lens system.
摘要:
Provided is a roll unit to be dipped in a surface treatment liquid of a copper foil, wherein a bearing box for housing a roil shaft is configured from two bearing boxes that are divisible, one of the bearing boxes is configured from a roll-side bearing box arranged on a roll main body-side and the other bearing box is configured from a shaft end-side bearing box arranged on the shaft end-side of the roll, a shaft sleeve covering an outer periphery of the roll shaft is provided in the roll-side bearing box and an oil seal is provided along an outer periphery of the shaft sleeve, and a bearing for rotatably supporting the shaft is disposed in the shaft end-side bearing box. Specifically, the present invention provides a roll unit to be used in electrochemical surface treatments such as roughening treatment, rust prevention treatment, and oxidized surface treatment (blackening treatment) to be continuously performed on a surface of a rolled copper foil or an electrolytic copper foil, and which is capable of inhibiting the abrasion and corrosion of the roll shaft of such roll unit by controlling the corrosion caused by the infiltration of the treatment liquid, and which enables the simple replacement of the bearing box, bearing, and other components.
摘要:
A large aperture super wide-angle lens system has an angle of view of 2&ohgr;=94° or more, an f-number of about 1.4, small variation in close-range aberrations, compactness, and high optical performance. The lens system includes, in order from an object, a negative lens group GN having negative refractive power which is fixed upon focusing, and a positive lens group GP having positive refractive power as a whole which is moved upon focusing. The positive lens group GP includes a front lens group GF having an aperture stop and a rear lens group GR having positive refractive power. Focusing at a close object is carried out by moving the front lens group GF and the rear lens group GR to the object side with different moving amounts. Prescribed conditional expressions are satisfied.
摘要:
To provide a zoom lens having wide field angle coverage, a zooming ratio of 3.5.times. or greater, and a large aperture such that F-number is on the order of F 2.8,a zoom lens is constituted having, in order from the object side thereof,a first lens group G1 having positive refractive power;a second lens group G2 having negative refractive power;and, at the image side thereof, one or more lens groups comprising a third lens group G3;wherein an airspace between the aforesaid first lens group G1 and the aforesaid second lens group G2 changes during a change in magnification;wherein the aforesaid second lens group G2 has, in order from the object side thereof,a negative lens component L1 comprising a negative lens presenting a concave surface toward the image side, a negative lens component L2 presenting a concave surface toward the object side, a positive lens component L3, a negative lens component L4, and a positive lens component L5;and wherein the following conditional expression (1) is satisfied:0
摘要:
An aberration-controllable optical system has a large angle of view and is capable of continuously varying spherical aberrations from negative values to positive values, including a point at which a sharp image can be produced. A master lens group includes a first sub lens group having a positive refractive power, a second sub lens group having a negative refractive power, and a third sub lens group having a positive refractive power in this order from the object side of the system. The converter lens group includes a positive lens element and a negative lens element in this order from the object side. The on-axis distance of the air gap which is formed between the positive lens element and the negative lens element can be controlled to mainly change the spherical aberrations in this system. When f.sub.m is a master lens group focal length and f.sub.C is a converter lens group focal length, the aberration-controllable optical system satisfies a condition: -1
摘要:
An inexpensive, compact and relatively easy-to-manufacture zoom lens is composed of a small number of lenses which can be mass produced favorably. The zoom lens includes a negative lens unit and a positive lens unit wherein the first lens unit includes, in order from the object side, a first negative meniscus lens component having a concave surface with stronger curvature facing the image side, a second negative meniscus lens component having a concave surface with stronger curvature facing the image side, and a third positive lens component having a convex surface with stronger curvature facing the object side. The second lens unit includes, in order from the object side, a fourth positive lens component, a fifth positive lens component, a sixth negative lens component, and a seventh positive lens component. At least one of the lens surfaces of the first negative meniscus lens component in the first lens group and the second negative meniscus lens component is aspheric. Additionally, the zoom lens satisfies the following conditions:0.6.ltoreq..vertline.f1.vertline./(fw.times.ft).sup.1/2
摘要翻译:廉价,紧凑且相对容易制造的变焦镜头由可以大量生产的少量透镜组成。 变焦透镜包括负透镜单元和正透镜单元,其中第一透镜单元从物体侧依次包括具有面向图像侧的具有较强曲率的凹面的第一负弯月形透镜部件,第二负弯月形透镜 具有朝向像侧的具有较强曲率的凹面的部件,以及具有面向物侧的具有较大曲率的凸面的第三正透镜部件。 第二透镜单元从物体侧依次包括第四正透镜部件,第五正透镜部件,第六负透镜部件和第七正透镜部件。 第一透镜组中的第一负弯月形透镜部件的透镜表面和第二负弯月形透镜部件中的至少一个透镜表面是非球面的。 另外,变焦透镜满足以下条件:0.6 = | f1 | /(fwxft)+ E,fra 1/2 + EE <1.0 1.2 = XII / fw 2.0 0.02 d56 / dII = 0.18。
摘要:
A zoom lens system including, in order from the object side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, in which zooming is effective by varying the spacing between the first lens unit and the second lens unit. The first lens unit has, in order from the object side, a negative meniscus lens element having a convex surface directed toward the object side, a negative lens element and a positive lens element. The second lens unit has, in order from the object side, a positive lens element having a convex surface directed toward the object side, a positive lens element, a cemented negative lens element composed of a positive lens element and a negative lens element, which are cemented together and a positive lens element. The first and second lens units and the elements thereof are positioned and arranged in prescribed relative positions.
摘要:
A zoom lens system, with both zooming and focusing functions, has a plurality of lens groups including at least two focusing lens groups which move differently from each other either in zooming or in focusing, wherein when a certain movement trace for zooming is expressed with a variable of rotation angle of a rotating barrel for defining a displacement amount of a lens group along an optical axis, a movement trace of the first focusing lens group is formed by a combination of a first focus cam with a first compensating zoom cam, a movement trace of an n-th focusing lens group is formed by a combination of an n-th focus cam with an n-th compensating zoom cam, and a movement trace of each movable non-focusing lens group taking no part in focusing is formed by a combination of one of the first to n-th compensating zoom cams with a zoom cam for the non-focusing lens group.