Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: An imaging lens includes: a movable lens group configured to travel to allow the imaging lens to come into focus; and a rearmost lens group arranged at a most-image-sided fixed position, and having negative refractive power. Following conditional expression is satisfied, ?2<ft/fr<?0.45??(1) where ft is a total focal length of the imaging lens in a condition that the imaging lens is in focus on an object at infinite, and fr is a focal length of the rearmost lens group.

Abstract: There is provided a lens unit equipped with multiple focus lenses provided inside a lens barrel, multiple actuators corresponding to the respective multiple focus lenses and configured to move each of the multiple focus lenses inside the lens barrel, and a control circuit configured to control movement of the multiple focus lenses according to different rules between a case of a position of each of the multiple focus lenses being inside a designated range of satisfactory optical performance, and a case of being outside the range.

Abstract: A zoom lens includes first to fourth lens groups having negative, positive, negative, and positive refractive power, respectively, and arranged in order from an object side. The first lens group includes negative lenses. The fourth lens group is configured of one positive lens. A zooming operation from wide end to telephoto end allows the first to third lens groups to travel along an optical axis, and allows the fourth lens group to be fixed. A focusing operation allows the third lens group to travel along the optical axis. The conditional expressions 1<(R1a+R1b)/(R1a?R1b)<5 and 2<(R4a+R4b)/(R4a31 R4b)<7 are satisfied where R1a and R1b are curvature radii on the object side and on the image side of a most-object-sided negative lens in the first lens group, respectively, and R4a and R4b are curvature radii on the object side and on the image side of the positive lens in the fourth lens group, respectively.

Abstract: An imaging lens includes: a movable lens group with total positive refractive power, including first and second sub lens groups; and an ever-fixed lens group that is ever-fixed. The imaging lens has first and second focusing modes for focusing operation in first and second focus ranges, respectively. The first focus range covers from an object at an infinite distance to an object at a first finite distance, and the second focus range covers from an object at a second finite distance shorter than the infinite distance to an object at a third finite distance shorter than the first finite distance. The first sub lens group is configured to be fixed and the second sub lens group is configured to travel, during each of the first and second focusing modes. Traveling of the movable lens group toward object plane allows switching from the first to second focusing modes.

Abstract: A zoom lens includes first to fourth lens groups having negative, positive, negative, and positive refractive power, respectively, and arranged in order from an object side. The first lens group includes negative lenses. The fourth lens group is configured of one positive lens. A zooming operation from wide end to telephoto end allows the first to third lens groups to travel along an optical axis, and allows the fourth lens group to be fixed. A focusing operation allows the third lens group to travel along the optical axis. The conditional expressions 1<(R1a+R1b)/(R1a?R1b)<5 and 2<(R4a+R4b)/(R4a?R4b)<7 are satisfied where R1a and R1b are curvature radii on the object side and on the image side of a most-object-sided negative lens in the first lens group, respectively, and R4a and R4b are curvature radii on the object side and on the image side of the positive lens in the fourth lens group, respectively.

Abstract: A zoom lens includes 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, and a fourth lens group having a positive refracting power. When the zoom lens is zoomed from a wide-angle end state to a telephoto end state, the first lens group is moved toward the object side so that a distance between the first and second lens groups increases and the third lens group is moved toward the object side so that a distance between the second and third lens groups decreases. The second lens group includes three lenses: negative, positive, and negative lenses in order from the object side to the image side. The third lens group includes three lenses: positive, negative, and positive lenses in order from the object side to the image side.

Abstract: An imaging lens includes: a movable lens group with total positive refractive power, including first and second sub lens groups; and an ever-fixed lens group that is ever-fixed. The imaging lens has first and second focusing modes for focusing operation in first and second focus ranges, respectively. The first focus range covers from an object at an infinite distance to an object at a first finite distance, and the second focus range covers from an object at a second finite distance shorter than the infinite distance to an object at a third finite distance shorter than the first finite distance. The first sub lens group is configured to be fixed and the second sub lens group is configured to travel, during each of the first and second focusing modes. Traveling of the movable lens group toward object plane allows switching from the first to second focusing modes.

Abstract: An imaging lens includes: a movable lens group configured to travel to allow the imaging lens to come into focus; and a rearmost lens group arranged at a most-image-sided fixed position, and having negative refractive power. Following conditional expression is satisfied, ?2<ft/fr<?0.45??(1) where ft is a total focal length of the imaging lens in a condition that the imaging lens is in focus on an object at infinite, and fr is a focal length of the rearmost lens group.

Abstract: A zoom lens includes 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, and a fourth lens group having a positive refracting power. When the zoom lens is zoomed from a wide-angle end state to a telephoto end state, the first lens group is moved toward the object side so that a distance between the first and second lens groups increases and the third lens group is moved toward the object side so that a distance between the second and third lens groups decreases. The second lens group includes three lenses: negative, positive, and negative lenses in order from the object side to the image side. The third lens group includes three lenses: positive, negative, and positive lenses in order from the object side to the image side.

Abstract: A zoom lens system has, in order from an object side, a first lens unit having a positive refractive power, a second lens unit having a negative refractive power, an aperture stop, a third lens unit having a positive refractive power, and a fourth lens unit having a positive refractive power; during magnification change, the first lens unit, the second lens unit, the third lens unit, the fourth lens unit and the aperture stop move; the first lens unit includes a negative lens and a positive lens in order from the object side; the second lens unit includes a negative lens and a positive lens in order from the object side; the third lens unit includes three or less lenses including one positive lens and one negative lens; and the fourth lens unit includes one positive lens.

Abstract: A zoom lens includes: a first lens group including a reflection member that deflects an optical path by 90 degrees and having positive refracting power; a second lens group having negative refracting power; a third lens group having positive refracting power; at least one lens group having negative refracting power and at least one lens group having positive refracting power disposed as a fourth lens group and the following lens groups, the first to third lens groups and the fourth and following lens groups arranged in this order from an object side toward an image side; and an aperture diaphragm disposed in the vicinity of the third lens group, wherein in zooming from a wide angle end state to a telescopic end state, the first lens group is fixed, the second lens group is moved toward the image side, and the fourth lens group is moved toward the object side, and the zoom lens satisfies the following conditional equation 1<(R1B+R21A)/(R1B?R21A)<20.

Abstract: The invention relates to a zoom lens and an imaging apparatus incorporating the same. More particularly, the invention is concerned with a zoom lens that is downsized for use with imaging apparatus inclusive of video cameras and digital cameras. The zoom lens comprises a positive first group G1, a negative lens group G2, a positive third group G3, a positive fourth group G4 and an aperture stop S. At least the first group G1 and the second group G2 move for zooming from the wide-angle end to the telephoto end. The first group G1, the third group G3 and the aperture stop S are positioned more on the object side in a state of the telephoto end than in a state of the wide-angle end. The spacing sandwiched between the first group G1 and the second group G2 grows wide, the spacing sandwiched between the second group G2 and the third group G3 becomes narrows, and the spacing sandwiched between the third group G3 and the fourth lens group G4 grows wide.

Abstract: A zoom optical system comprising, in order from an object side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, a space between the lens units being changed to thereby perform zooming and focusing, wherein the first lens unit is constituted of a negative lens.

Abstract: The invention relates to a less costly zoom lens that can offer a sensible tradeoff between size reductions and high zoom ratios with a well-kept image quality, and that lends itself to an electronic imaging device such as a CCD or CMOS. The zoom lens comprises a positive first lens group G1, a negative second lens group G2, a positive third lens group G3 and a positive fourth lens group G4, wherein zooming is implemented by changing the space between adjacent lens groups. The first lens group G1 comprises one positive lens, the second lens group G2 comprises two lenses, and the fourth lens group G4 comprises one positive lens. The zoom lens satisfies condition (1) needed for making sure an ideal situation for the zoom ratio and low costs and condition (2) needed for the first lens group to comprise a minimum one lens and to hold back chromatic aberration of magnification as much as possible.

Abstract: A zoom optical system comprising, in order from an object side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a third lens unit having a positive refractive power, a space between the lens units being changed to thereby perform zooming and focusing, wherein the first lens unit is constituted of a negative lens.