摘要:
There are provided four lens groups including a first lens group G1 having a positive refractive power, a second lens group G2 having a negative refractive power, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a positive refractive power, sequentially arranged from an object side. When a positional state of lenses is varied from a wide-angle-end state to a telephoto-end state, the second lens group is moved to an image side, the fourth lens group is moved for compensating a variation in a position of an image plane caused by the movement of the second lens group, and the first lens group and the third lens group are fixed along the optical axis. An aperture stop S is disposed at the object side of the third lens group. The third lens group includes a negative sub-lens group having a negative refractive power, and a positive sub-lens group disposed at the image side of the negative sub-lens group with an airspace interposed therebetween, the positive sub-lens group having a positive refractive power. In addition, the following conditional expression (1) is satisfied: 0.4
摘要:
A zoom lens is disclosed which is superior in reduction of the lens diameter and can suppress degradation in performance while a high zoom ratio is achieved. The zoom lens is formed as a zoom lens of a four-group configuration having positive, negative, positive and positive groups. The second and fourth lens groups move whereas the first and third lens groups are fixed. An aperture stop is disposed on the object side of the third lens group. The third lens group includes negative and positive sub groups with an air distance left therebetween. The positive sub group is shiftable perpendicularly to the optical axis to shift an image substantially perpendicularly. A conditional expression 1.4
摘要:
A variable focal length lens system includes at least three lens groups, in order from an object side, a first lens group G1, a second lens group G2, and a third lens group G3. When the lens group positions are changed from a wide-angle end state to a telephoto end state, each lens group moves from a state focused at infinity to a state focused at near object, in order from a state focused at infinity in the wide-angle end state to a state focused at near object in the telephoto end state. G2 has an aperture diaphragm S, and lens elements are arranged to both object and image side of the aperture diaphragm S. When the lens group positions are changed from the wide-angle end state to the telephoto end state, G1 and G2 moves such that a moving ratio of G2 to G1 is always same, and G3 moves such that a space between G2 and G3 increases when a focusing state in a predetermined focal length changes from infinity to near object, and the space decrease when a focusing state and a focal length state change from near object in the predetermined focal length state to infinity in the next focal length state.
摘要:
An optical document scanning method and apparatus having a driving system which drives each of the lens groups collectively forming the optical scanning apparatus in an optical axis direction to lens positions corresponding to a given designed-scanning magnification; and a detecting system which detects the actual scanning magnification of the optical scanning system at the lens positions corresponding to the given designed-scanning magnification, whereby to substantially match the actual scanning magnification to the given designed-scanning magnification, the driving system drives each of the lens groups in the optical axis direction by a given amount corresponding to any difference between the actual scanning magnification and the given designed-scanning magnification.
摘要:
A variable magnification optical system of reduced size and increased zoom ratio is provided. According to one aspect, a positive lens group having positive refractive power which is disposed closest to an object and an end lens group disposed closest to an image are provided. When lens group positions are changed so that the system changes from the wide-angle state to the telephoto state, the positive lens group and the end lens group move toward the object. In this case, a ratio of the moving amount of the positive lens group to that of the end lens group from the wide-angle state to a given state satisfies a particular condition. A simplified barrel structure results when a particular first supporting element for supporting a first lens group which moves along an optical axis and a particular second supporting element for supporting an end lens group located closer to an image than the first lens group are provided. The second supporting element moves integrally with the end lens group along the optical axis. The second supporting element transmits a rotational driving force applied thereto to the first supporting element and moves along the optical axis in accordance with the rotational driving force. The first supporting element moves along the optical axis in accordance with the rotational driving force transmitted thereto via the second supporting element.
摘要:
A small wide-angle zoom lens having good performance, in order from the object side, comprises at least a first lens group G1 having a negative refractive power, a second lens group G2 having a positive refractive power, and a third lens group G3 having a negative refractive power. During zooming from a maximum wide-angle state to a maximum telephoto state, each lens group can move toward the object side so that the distance between the first lens group G1 and the second lens group G2 decreases and the distance between the second lens group G2 and the third lens group G3 decreases. The second lens group can comprise first, second and optional third lens group units. The zoom lens is configured to satisfy various conditions to achieve advantageous results.
摘要:
A high variable power zoom lens system that performs image formation and also covers a wide-angle area. The zoom lens includes a first lens group having a positive refractive power arranged at the object side, a second lens group having a negative refractive power adjacent to the image side of the first lens group and a third lens group having a positive refractive power adjacent to the image side of the second lens group. The second lens group includes, in order from the object side, a double concave lens component, a positive lens having a convex surface facing the object side and a negative lens with the concave surface facing the object side. The zoom lens system preferably satisfies the following Conditions: 0.8
摘要:
A camera having an apparatus for correcting parallax includes viewfinder optical system for viewing an object. A shooting lens system for photographing the object is disposed such that the optical axis of the shooting lens system is different from the optical axis of the viewfinder optical system. The shooting lens system includes a correcting lens group such that image shift is accomplished by decentering the correcting lens group. A focusing lens group, spaced from the correcting lens group, is moveable along the optical axis of the shooting lens system. Parallax that is created by changes in the position of the object is corrected by accomplishing an image shift by the shooting lens system.
摘要:
To provide a zoom lens in which focussing is possible with a small displacement and which is capable of close range focussing with superior imaging performance. The present invention provides a zoom lens capable of focussing at close range, of the type equipped with at least two lens units having negative refractive powers and arranged so as to be adjacent to each other, wherein focussing on close range objects is accomplished by causing one of the at least two lens units to move along the optical axis; and, the conditions: (.beta.a-.beta.a.sup.-1).sup.-2 0 are satisfied, where .beta.a is the lateral magnification of the close range focussing lens unit at the maximum telephoto state in an infinite focus state, and .beta.b is the lateral magnification of the close range focussing lens unit at the maximum wide-angle state in an infinite focus state.
摘要翻译:为了提供一种变焦透镜,其中可以以小位移进行聚焦,并且能够以优异的成像性能聚焦。 本发明提供一种能够在近距离聚焦的变焦透镜,该变焦透镜配备有具有负屈光力的至少两个透镜单元并且被布置为彼此相邻,其中聚焦在近距离物体上是通过使一个 所述至少两个透镜单元沿着所述光轴移动; 并且,条件(βa-βa-1)-2 <0.8 beta a /βb> 0满足,其中βa是近距离聚焦透镜单元在无限焦中的最大远摄状态下的横向放大率 状态,βb是近距离聚焦透镜单元在无限焦点状态下处于最大广角状态的横向放大率。
摘要:
An optical system includes, in the following order from the 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 negative refractive power, a fourth lens unit having a positive refractive power, a fifth lens unit having a positive refractive power, and a sixth lens unit having a negative refractive power. At least the first and sixth lens units move toward the object side upon changing the focal length from the maximum wide-angle state to the maximum telephoto state in such a way that the gap between the first and second lens units increases, the gap between the third and fourth lens units decreases, and the gap between the fifth and sixth lens units decreases.