JP6433164B2 - Zoom lens and imaging apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens, for example, as an imaging optical system of an imaging device using a solid-state imaging device such as a video camera, an electronic still camera, a television camera, a surveillance camera, or a camera using a silver salt film. Is preferred.

  In recent years, an imaging optical system used in an imaging apparatus is required to be a zoom lens having a small overall system, a high zoom ratio, and high optical performance. Among these, a zoom lens used in an imaging apparatus such as a television camera is very unsightly when there is a change in the field of view (change in lateral magnification) during focusing. Therefore, there is a demand for a small change in the field of view due to focusing. Conventionally, as a zoom lens used for a television camera, a positive lead type in which a lens group having a positive refractive power is disposed closest to the object side, and a zoom lens that reduces a change in the field of view during focusing is known ( Patent Documents 1 and 2).

  In Patent Documents 1 and 2, in order from the object side to the image plane side, a first lens group having a positive refractive power, a second lens group having a negative refractive power, a third lens group having a positive or negative refractive power, There is disclosed a zoom lens that includes a fourth lens unit having refractive power and in which the second and third lens units move during zooming. In Patent Documents 1 and 2, in order from the object side to the image surface side, the first lens group is a first partial group having a negative refractive power, a second partial group having a positive refractive power, and a third partial group having a positive refractive power. An inner focus method is used in which focusing is performed by moving the second partial group. By adopting such a configuration, an image field change caused by focusing is reduced.

Japanese Patent Publication No.59-4686 JP-A-6-242378

  Zoom lenses used in imaging devices such as TV cameras and video cameras are small in size, have high image quality (high resolution) over the entire zoom range, and have little change in the field of view during focusing. It is requested. In order to obtain a zoom lens that satisfies these requirements, it is important to appropriately configure a lens group that is moved during zooming, a partial group that is moved during focusing, and the like.

  For example, in the above-described positive lead type zoom lens, when the telephoto at the wide-angle end, the focal length of the first lens unit is increased, and the entire system is reduced in size, and the field change due to focusing is suppressed. It becomes difficult. It is important to appropriately set the lens configuration of the first lens group and the paraxial refractive power arrangement of the first lens group, etc., in order to reduce the field of view due to focusing while reducing the size of the entire system. It becomes.

The present invention may, for example, to lack of Ekai change due to focusing, and to provide a point at advantageous zoom lens of high optical performance that cotton in the zoom range of interest.

The zoom lens of the present invention includes, in order from the object side to the image plane side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves for zooming, and zooming. A zoom lens composed of an intermediate lens group having at least one lens group that moves for the purpose of zooming, and a rear lens group that does not move for zooming and has a positive refractive power,
The first lens group includes an eleventh part group having a negative refractive power that does not move for focusing, and a twelfth part having a positive refractive power that moves toward the image plane side for focusing from an object at infinity to a short-distance object . group, for focusing consists thirteenth subgroup of positive refractive power and does not move, the focal length of the zoom lens at the wide angle end fw, the focal length of the first lens group f1, the twelfth subgroup F1 ; the thickness of the first lens group on the optical axis is DL1, the thickness of the second lens group on the optical axis is DL2, and the first lens when focusing on an object at infinity The distance from the image side lens surface vertex of the first lens group to the image side principal point of the first lens group is Ok_1, and the distance from the object side lens surface vertex of the second lens group to the object side principal point of the second lens group. distance as a O1_2 the,
0.5 <f12 / f1 <2.0
0.5 <f1 / fw <5.0
-0.5 <Ok_1 / DL1 <0.2
0.1 <O1_2 / DL2 <0.8
It is characterized by satisfying the following conditional expression.

According to the present invention, lack of Ekai change due to focusing, and a point in an advantageous zoom lens of high optical performance that cotton in the entire zoom range.

Sectional view of the lens at the wide-angle end of Embodiment 1 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 1 of the present invention. Sectional view of the lens at the wide-angle end of Embodiment 2 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 2 of the present invention. Sectional view of the lens at the wide-angle end of Embodiment 3 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 3 of the present invention. Cross-sectional view of a lens at a wide angle end according to Embodiment 4 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 4 of the present invention. Lens cross-sectional view at the wide angle end according to Embodiment 5 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 5 of the present invention. Cross-sectional view of a lens at a wide angle end according to Embodiment 6 of the present invention (A), (B), (C) Aberration diagrams at zoom positions in Example 6 of the present invention. (A), (B) Optical path diagram in zoom lens of the present invention Optical path diagram of the zoom lens of the present invention (A), (B) Optical path diagram in zoom lens of the present invention (A), (B) Optical path diagram in zoom lens of the present invention (A), (B) Optical path diagram in zoom lens of the present invention Schematic diagram of main parts of an imaging apparatus of the present invention

  Embodiments of a zoom lens and an image pickup apparatus having the same according to the present invention will be described below with reference to the accompanying drawings.

  The zoom lens of the present invention is as follows in order from the object side to the image plane side. For zooming, a first lens group having a positive refractive power that does not move, a second lens group having a negative refractive power that moves during zooming, an intermediate lens group that has one or more lens groups that move during zooming, and for zooming Is constituted by a rear lens group having a fixed positive refractive power. The first lens group is an eleventh partial group having a negative refractive power that is stationary for focusing, and a twelfth partial group having a positive refractive power that moves toward the image plane when focusing from an object at infinity to a short distance object. For focusing, it consists of a thirteenth partial group of positive refractive power that does not move.

  FIG. 1 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of the zoom lens according to Embodiment 1 of the present invention. 2A, 2B, and 2C are longitudinal aberration diagrams at the wide-angle end, the focal length 118.30 mm, and the telephoto end, respectively, when focusing on the object at infinity according to the first embodiment. However, the value of the focal length is a value when a numerical example described later is expressed in mm. This is the same in all the following embodiments. Example 1 is a zoom lens having a zoom ratio of 2.86, a half angle of view (shooting half angle of view) of 12.52 degrees at the wide angle end, and a half angle of view of 4.45 degrees at the telephoto end.

  FIG. 3 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of the zoom lens according to Embodiment 2 of the present invention. 4A, 4B, and 4C are longitudinal aberration diagrams at the wide-angle end, the focal length of 84.50 mm, and the telephoto end, respectively, when focusing on the object at infinity according to the second embodiment. The second exemplary embodiment is a zoom lens having a zoom ratio of 2.86, a half field angle (shooting half field angle) of 17.28 degrees at the wide angle end, and a half field angle of 6.21 degrees at the telephoto end.

  FIG. 5 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of the zoom lens according to Embodiment 3 of the present invention. 6A, 6B, and 6C are longitudinal aberration diagrams at the wide-angle end, the focal length of 135.20 mm, and the telephoto end, respectively, when focusing on an infinitely distant object according to the third embodiment. Example 3 is a zoom lens having a zoom ratio of 2.86, a half angle of view (shooting half angle of view) of 11.00 degrees at the wide angle end, and a half angle of view of 3.89 degrees at the telephoto end.

  FIG. 7 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of the zoom lens according to Embodiment 4 of the present invention. FIGS. 8A, 8B, and 8C are longitudinal aberration diagrams at the wide-angle end, the focal length of 118.09 mm, and the telephoto end, respectively, when focusing on an object at infinity according to the fourth embodiment. Example 4 is a zoom lens having a zoom ratio of 2.86, a half angle of view (shooting half angle of view) of 12.52 degrees at the wide angle end, and a half angle of view of 4.45 degrees at the telephoto end.

  FIG. 9 is a lens cross-sectional view when focusing on an object at infinity at the wide-angle end of the zoom lens according to Embodiment 5 of the present invention. FIGS. 10A, 10B, and 10C are longitudinal aberration diagrams at the wide-angle end, the focal length of 140.00 mm, and the telephoto end, respectively, when focusing on the object at infinity according to the fifth embodiment. The fifth exemplary embodiment is a zoom lens having a zoom ratio of 4.00, a half field angle (shooting half field angle) of 12.52 degrees at the wide angle end, and a half field angle of 3.18 degrees at the telephoto end.

  FIG. 11 is a lens cross-sectional view of the zoom lens according to Embodiment 6 of the present invention when focusing at infinity at the wide angle end. FIGS. 12A, 12B, and 12C are longitudinal aberration diagrams at the wide-angle end, the focal length of 118.32 mm, and the telephoto end, respectively, when focusing on the object at infinity according to the sixth embodiment. Example 6 is a zoom lens having a zoom ratio of 2.86, a half angle of view (shooting half angle of view) of 12.52 degrees at the wide angle end, and a half angle of view of 4.45 degrees at the telephoto end.

  FIGS. 13A and 13B are optical path diagrams of on-axis paraxial rays and pupil paraxial rays at the wide-angle end and the telephoto end of the zoom lens when the third lens group has a negative refractive power, respectively. FIG. 14 shows the arrangement of the refractive power in the paraxial region closer to the object side than the aperture stop at the wide-angle end of the zoom lens when the third lens group has a positive refractive power, and the case where a paraxial ray passes from the aperture stop to the object side. FIG. FIGS. 15A, 15B, 16A, 16B, 17A, and 17B respectively show the first lens group and the first lens group at the wide angle end of the zoom lens according to the embodiment of the present invention. It is explanatory drawing of refractive power arrangement | positioning of the paraxial area | region of 2 lens groups. FIG. 18 is a schematic diagram of a main part of the imaging apparatus of the present invention.

  In the lens cross-sectional view, arrows indicate the movement trajectory of each lens unit during zooming from the wide-angle end to the telephoto end. The arrow related to Focus indicates the moving direction of the subgroup during focusing from an infinitely distant object to a close object.

  In FIGS. 1, 3, 5, and 7, U1 is a first lens unit having a positive refractive power that does not move for zooming. The first lens unit U1 includes a partial group that moves during focusing. U2 is a second lens unit (variator lens unit) having a negative refractive power for zooming that moves toward the image plane during zooming from the wide-angle end (short focal length end) to the telephoto end (long focal length end). UM is an intermediate lens group, which moves in conjunction with the magnification change of the second lens group U2, and from a third lens group (compensator lens group) U3 having a positive refractive power that corrects image plane variation accompanying the magnification change. It has become.

  In Examples 1 to 3, the third lens unit U3 moves along a locus convex toward the image side during zooming from the wide-angle end to the telephoto end. In Example 4, the third lens unit U3 moves to the object side during zooming from the wide-angle end to the telephoto end. SP is an aperture stop that does not move during zooming, and is disposed on the image side of the third lens unit U3. UR is a rear lens group, and comprises a fourth lens group (relay lens group) U4 having a positive refractive power that does not move for zooming.

  In FIG. 9, U1, U2, and UR (U4) are the same as those in the first to fourth embodiments. UM is an intermediate lens unit, which moves in conjunction with zooming of the second lens unit U2, and from a third lens unit (compensator lens unit) U3 having a negative refractive power that corrects image plane fluctuations accompanying zooming. It has become. The third lens unit U3 moves along a locus convex toward the object side during zooming from the wide-angle end to the telephoto end.

In FIG. 11, U1 and U2 are the same as those in the first embodiment. UM is an intermediate lens group, the positive refractive power of the third lens group U3 performing at least one of correction of image plane variation due to zooming action or zooming for zooming to the wide-angle end or al telephoto end, It has a fourth lens group U4 having a positive refractive power. UR is a rear lens group, for zooming consists immobile positive refractive power, and a fifth lens unit (relay lens unit).

  In each lens cross-sectional view, IP is an image plane, which corresponds to the imaging plane of a solid-state imaging element (photoelectric conversion element). In each embodiment, the lens group or the partial group refers to an aggregate including one or more lenses separated by a lens interval that changes during at least one of focusing and zooming.

  In the aberration diagrams, spherical aberration is represented by e-line (solid line) and g-line (dotted line). Astigmatism is represented by the e-line meridional image plane (ΔM) (dotted line) and the e-line sagittal image plane (ΔS) (solid line). The lateral chromatic aberration is represented by the g-line. Fno is an F number, and ω is a half angle of view (degrees). In all the aberration diagrams, the spherical aberration is 0.4 mm, the astigmatism is 0.4 mm, the distortion is 5%, and the chromatic aberration of magnification is 0.05 mm. The wide-angle end and the telephoto end are zoom positions when the second lens unit U2 for zooming is positioned at both ends of a range in which the mechanism can move on the optical axis.

  Next, the lens configuration of each lens group of Example 1 will be described. Hereinafter, it is assumed that the lenses of each lens group are arranged in order from the object side to the image plane side. The eleventh partial group U11 includes a positive lens and two negative lenses. The twelfth partial group U12 includes a cemented lens in which a negative lens and a positive lens are cemented. The thirteenth partial group U13 includes a positive lens, a negative lens, and a positive lens.

  The second lens unit U2 includes a cemented lens obtained by cementing a negative lens and a positive lens, and two negative lenses. The third lens unit U3 includes a positive lens and a cemented lens in which a positive lens and a negative lens are cemented. The fourth lens unit U4 includes two positive lenses, a cemented lens in which a positive lens and a negative lens are cemented, and two positive lenses. In the second embodiment, the lens configuration of each lens group is the same as that of the first embodiment.

  In Example 3, the lens configurations of the eleventh partial group U11, the twelfth partial group U12, the thirteenth partial group U13, the third lens group U3, and the fourth lens group U4 are the same as those of the first example. In Example 3, the second lens unit U2 includes a cemented lens in which a positive lens and a negative lens are cemented, and a negative lens.

  In Example 4, the lens configurations of the eleventh partial group U11, the twelfth partial group U12, the thirteenth partial group U13, the second lens group U2, and the third lens group U3 are the same as those in the first example. In Example 4, the fourth lens unit U4 includes a cemented lens in which a negative lens and a positive lens are cemented, two positive lenses, and a cemented lens in which a negative lens and a positive lens are cemented.

  In Example 5, the lens configurations of the eleventh partial group U11, the twelfth partial group U12, the thirteenth partial group U13, and the second lens group U2 are the same as those in the first example. In Example 5, the third lens unit U3 includes a cemented lens in which a negative lens and a positive lens are cemented. The fourth lens unit U4 includes two positive lenses, a cemented lens in which a positive lens and a negative lens are cemented, a positive lens, a cemented lens in which a negative lens and a positive lens are cemented, a negative lens, two positive lenses, and a negative lens. ing.

  In Example 6, the lens configurations of the eleventh partial group U11, the twelfth partial group U12, the thirteenth partial group U13, and the second lens group U2 are the same as those of the first example. In Example 6, the third lens unit U3 includes a cemented lens in which a negative lens and a positive lens are cemented. The fourth lens unit U4 is composed of one positive lens. The fifth lens unit U5 includes two positive lenses, a cemented lens obtained by cementing a positive lens and a negative lens, and two positive lenses.

  The zoom lens of the present invention is as follows in order from the object side to the image plane side. For zooming, a first lens unit U1 having a positive refractive power that does not move, a second lens unit U2 having a negative refractive power that moves during zooming, an intermediate lens unit UM that has one or more lens groups that move during zooming, and zooming For this purpose, the rear lens unit UR has a fixed positive refractive power.

The first lens unit U1 is as follows in order from the object side to the image plane side. For focusing, an eleventh subgroup U11 having a negative refractive power that does not move, a twelfth subgroup U12 having a positive refractive power that moves to the image side in order to focus from an object at infinity to a near object, for focusing It is composed of 13 subgroup U13 having a positive refractive power and does not move. The focal length of the entire system at the wide angle end is fw, the focal length of the first lens unit U1 is f1, and the focal length of the twelfth partial group U12 is f12. At this time,
0.5 <f12 / f1 <2.0 (1)
0.5 <f1 / fw <5.0 (2)
The following conditional expression is satisfied.

  FIGS. 13A and 13B are close to the axis when focusing on an object at infinity at the wide-angle end and the telephoto end of the zoom lens corresponding to Example 5 in which the third lens unit U3 has negative refractive power. It is an optical path diagram of an axial ray and a pupil paraxial ray. Let fw and ft be the focal lengths of the entire system at the wide-angle end and the telephoto end, respectively.

  13A and 13B, the incident heights at the wide-angle end of the on-axis paraxial rays of the first lens unit U1 to the fourth lens unit U4 are h1w to h4w, respectively. The incident heights at the telephoto end are h1t to h4t, respectively. The incident heights at the wide-angle end of the pupil paraxial rays are defined as H1w to H4w, respectively. The incident heights at the telephoto end are H1t to H4t, respectively. The refractive powers of the first lens unit U1 to the fourth lens unit U4 are Φ1 to Φ4, respectively.

  The main point interval between the first lens unit U1 and the second lens unit U2 at the wide angle end is L1w, the main point interval between the second lens unit U2 and the third lens unit U3 at the wide angle end is L2w, and the third lens unit U3 at the wide angle end. And the distance between the principal points of the fourth lens unit U4 is L3w. The main point interval between the first lens unit U1 and the second lens unit U2 at the telephoto end is L1t, the main point interval between the second lens unit U2 and the third lens unit U3 at the telephoto end is L2t, and the third lens unit U3 at the telephoto end. And the distance between the principal points of the fourth lens unit U4 is L3t.

  14 to 17, Φ11 is the refractive power (the reciprocal of the focal length) of the eleventh subgroup U11. Φ12 (Φ12 ′) is the refractive power of the twelfth subgroup U12. Φ13 (Φ13 ′) is the refractive power of the thirteenth partial group U13.

  e11 (e11 ') is the principal point interval between the eleventh partial group U11 and the twelfth partial group U12. e12 (e12 ') is the principal point interval between the twelfth partial group U12 and the thirteenth partial group U13. e13w (e13w ') is the principal point interval between the thirteenth partial group U13 and the second lens group U2. L1w ′ is the principal point interval between the first lens unit U1 and the second lens unit U2. f1 'is the focal length of the first lens unit U1.

  As shown in FIG. 13, on-axis paraxial rays when focused on an object at infinity are normalized to a focal length fw = 1, and are incident on the optical system parallel to the optical axis at an incident height h1w = 1. An axial ray. The pupil paraxial ray is a paraxial ray that is normalized to the focal length fw = 1 and passes through the intersection between the entrance pupil of the optical system and the optical axis, among rays incident on the maximum image height of the imaging surface. It is assumed that the object is on the left side of the optical system, and light rays incident on the optical system from the object side travel from left to right.

  The relationship between the refractive power arrangement in the paraxial region at the wide-angle end and the change in the field of view (shooting field angle) due to focusing will be described with reference to FIG. FIG. 14 shows a refractive power arrangement in the paraxial region closer to the object side than the aperture stop SP at the wide-angle end of the zoom lens corresponding to Embodiments 1 to 4 in which the third lens unit U3 has positive refractive power, and the object from the aperture stop SP to the object. It is an optical path figure at the time of letting a paraxial ray pass to the side.

  FIG. 14 shows the traveling state of the light beam as being opposite to the traveling direction of the solid light beam for convenience. As shown in FIG. 14, the pupil paraxial rays that have passed from the aperture stop SP toward the object side are the third lens group U3, the second lens group U2, the thirteenth partial group U13, the twelfth partial group U12, and the eleventh partial group. Go through U11. Then, the image height Y of the subject position Sobj at the distance Lobj is reached from the eleventh partial group U11 to the image side. In order to suppress the change in the field due to the focusing, it is necessary to suppress the half-field change amount Δy of the pupil paraxial ray at the subject position Sobj when the twelfth subgroup U12 moves for focusing. . Here, the incident angle of the pupil paraxial ray to the twelfth subgroup U12 in the paraxial region at the wide angle end is

The refractive power of the eleventh partial group U11 is Φ11, and the refractive power of the twelfth partial group U12 is Φ12. The difference between the distance a from the imaginary point A to the twelfth partial group U12 with respect to the twelfth partial group U12 and the distance c from the twelfth partial group U12 to the virtual image point C at the imaging position when focusing on the subject position Sobj is obtained. Let δ. Let Δx be the amount of movement of the twelfth subgroup U12 when focusing from the object at infinity to the subject position Sobj. The amount of change Δy of the half field at the subject position Sobj when focusing from the object at infinity to the subject position Sobj is approximately:

It is represented by The incident height of the paraxial ray of the eleventh subgroup U11 at the wide angle end when focusing on an infinite object is H11w, and the incident angle is

, The half-field y at the subject position Sobj is

It is represented by Therefore, the change rate γ of the field at the subject position Sobj when focusing from the object at infinity to the subject position Sobj is approximately:

It is represented by In order to suppress the amount of change Δy of the half field due to focusing, it is particularly necessary to appropriately set the lens configuration and paraxial arrangement of the first lens unit U1. In particular, it is important to reduce the movement amount Δx. The same applies to the case where the third lens unit U3 as shown in FIG. 13 has a negative refractive power, and the case where the portion from the thirteenth partial group U13 to the aperture stop SP is composed of four or more groups.

  Conditional expression (1) defines the ratio of the focal lengths of the first lens unit U1 and the twelfth partial group U12. Satisfying conditional expression (1) reduces the change in the field of view (change in the shooting field of view) due to the miniaturization of the entire system and focusing at the wide-angle end, and corrects various aberrations satisfactorily. The movement amount Δx of the twelfth group U12 that moves during focusing from an infinitely distant object to a close object increases as the focal length of the twelfth subgroup U12 increases. For this reason, in order to reduce the change in the field of view accompanying focusing, it is necessary to shorten the focal length of the twelfth subgroup U12.

  If the upper limit of conditional expression (1) is exceeded, the refracting power of the twelfth partial group U12 will be insufficient, and the amount of movement Δx of the twelfth partial group at the time of focusing will increase, resulting in a reduction in size and focusing of the zoom lens. It becomes difficult to reduce the field change. If the lower limit of conditional expression (1) is exceeded and the refracting power of the twelfth partial group U12 becomes too strong with respect to the refracting power of the first lens group U1, it will be difficult to correct aberration fluctuations associated with focusing. More preferably, the numerical range of conditional expression (1) is set as follows.

0.9 <f12 / f1 <1.8 (1a)
Conditional expression (2) defines the ratio between the focal length of the entire system at the wide-angle end and the focal length of the first lens unit U1. By satisfying conditional expression (2), the zoom lens can be easily telephoto and various aberrations are favorably corrected while downsizing the entire system.

  If the upper limit of conditional expression (2) is exceeded, the focal length of the first lens unit U1 will increase, the effective diameter of the first lens unit U1 and the total lens length will increase, and it will be difficult to downsize the entire system. If the lower limit of conditional expression (2) is exceeded, the focal length of the first lens unit U1 will be too short, making the zoom lens telephoto disadvantageous, and it will be difficult to correct spherical aberration, axial chromatic aberration, etc. at the telephoto end. Become. More preferably, the numerical range of conditional expression (2) is set as follows.

1.4 <f1 / fw <2.1 (2a)
With the configuration as described above, a zoom lens is achieved in which the entire system is compact and the change in the field of view at the wide-angle end due to focusing is reduced while achieving telephoto.

  In each embodiment, it is more preferable to satisfy one or more of the following conditional expressions. The focal length of the eleventh partial group U11 is set to f11. Let the focal length of the thirteenth partial group U13 be f13. Let the focal length of the second lens unit U2 be f2. Let the focal length of the third lens unit U3 be f3. The thickness of the first lens unit U1 on the optical axis is DL1, and the distance between the principal points of the eleventh partial group U11 and the twelfth partial group U12 when focusing on the object at infinity is e11, focusing on the object at infinity. The principal point interval between the twelfth partial group U12 and the thirteenth partial group U13 is e12.

  The thickness of the second lens unit U2 on the optical axis is DL2, and from the lens surface vertex on the image side of the first lens unit U1 when focusing on an object at infinity to the image side principal point position of the first lens unit Let the distance be Ok_1. A distance from the vertex of the object-side lens surface of the second lens unit U2 to the object-side principal point position of the second lens unit is defined as O1_2. Let R1 be the radius of curvature of the object-side lens surface of the positive lens closest to the object side in the first lens unit U1, and let R2 be the radius of curvature of the image-side lens surface of the positive lens. Let β3w be the lateral magnification of the third lens unit U3 at the wide-angle end when focusing on an object at infinity.

At this time, one or more of the following conditional expressions should be satisfied.
−2.5 <f11 / f1 <−0.5 (3)
−1.5 <f12 / f11 <−0.5 (4)
0.3 <f13 / f1 <1.5 (5)
−0.3 <e11 / DL1 <0.4 (6)
0.05 <e12 / DL1 <0.60 (7)
-0.5 <Ok_1 / DL1 <0.2 (8)
0.1 <O1_2 / DL2 <0.8 (9)
-11.0 <(R1 + R2) / (R1-R2) <-2.0 (10)
0.2 <| f2 / f3 | <0.8 (11)
−1.40 <1 / β3w <2.10 (12)

  Next, the technical meaning of each embodiment will be described. Conditional expression (3) defines the ratio of the focal lengths of the first lens unit U1 and the eleventh partial unit U11. By satisfying conditional expression (3), various aberrations are corrected well while achieving telephoto zoom lens and miniaturization of the entire system. When the lower limit of conditional expression (3) is exceeded, the negative focal length of the eleventh partial group U11 becomes long (the absolute value of the negative focal length becomes large), and the effective diameter and the total lens length of the eleventh partial group U11 are large. Therefore, it is difficult to reduce the size of the entire system.

  If the upper limit of conditional expression (3) is exceeded, the negative focal length of the eleventh subgroup U11 is too short (the absolute value of the negative focal length becomes small), which is disadvantageous for telephoto zooming and wide angle. It becomes difficult to correct distortion and astigmatism at the end, and spherical aberration at the telephoto end. More preferably, the numerical range of conditional expression (3) is set as follows.

−1.5 <f11 / f1 <−1.0 (3a)
Conditional expression (4) defines the ratio of the focal lengths of the eleventh subgroup U11 and the twelfth subgroup U12. Conditional expression (5) defines the ratio of the focal lengths of the first lens unit U1 and the thirteenth partial unit U13. By satisfying conditional expressions (4) and (5), the zoom lens is telephoto and the entire system is miniaturized, and the change in the field due to focusing is reduced at the wide-angle end, and various aberrations are improved. It is corrected.

  In each embodiment, in order to achieve a telephoto zoom lens and to reduce the size of the first lens unit U1, it is necessary to configure as follows. The focal length f1 of the first lens unit U1 and the principal point interval L1w at the wide-angle ends of the first lens unit U1 and the second lens unit U2 are kept short, and the thickness of the first lens unit U1 on the optical axis is shortened. It is necessary to do.

  Specifically, it is necessary to increase the refractive power of the twelfth partial group U12 and the thirteenth partial group U13 and to dispose the image side principal point of the first lens group U1 closer to the object side. Accordingly, as shown in FIGS. 15A and 15B, the light of the first lens unit U1 is shortened by reducing the principal point interval e13w between the thirteenth partial group U13 and the second lens unit U2 at the wide-angle end. The thickness on the shaft can be shortened.

  Furthermore, the movement amount Δx of the twelfth partial group U12 when focusing from an infinite object to a short-distance object increases as the focal length f12 of the twelfth partial group U12 increases. On the other hand, as shown in FIG. 14, the incident angle of the pupil paraxial ray on the twelfth partial group U12U12

Increases as the focal length f13 of the thirteenth partial group U13 increases. Therefore, from Equation 1, in order to reduce the field change due to focusing, it is necessary to shorten the focal length f12 of the twelfth partial group U12 and the focal length f13 of the thirteenth partial group U13.

  If the upper limit of conditional expression (4) is exceeded and the positive refractive power of the twelfth partial group U12 becomes stronger than the negative refractive power (the absolute value of the negative refractive power) of the eleventh partial group U11 (negative focus) When the absolute value of the distance increases), it becomes difficult to correct aberration fluctuations accompanying focusing. Furthermore, the negative focal length of the eleventh subgroup U11 increases (the absolute value of the negative focal length increases), and the effective diameter and lens thickness of the eleventh subgroup U11 increase, making it difficult to reduce the size of the zoom lens. It becomes.

  If the lower limit of conditional expression (4) is exceeded and the refracting power of the twelfth subgroup U12 is insufficient, it becomes difficult to reduce the size of the zoom lens and to reduce the change in field due to focusing. Further, the negative refractive power (the absolute value of the negative refractive power) of the eleventh partial group U11 becomes stronger (larger) than the absolute value of the refractive power of the twelfth partial group U12, and the small size of the thirteenth partial group U13. It is difficult to correct spherical aberration, axial chromatic aberration, and the like at the telephoto end.

  If the upper limit of conditional expression (5) is exceeded, the positive refractive power of the thirteenth partial group U13 will be insufficient, and the incident angle of the pupil paraxial ray on the twelfth partial group U12

It is difficult to reduce the image field change due to focusing. Further, the refractive power of the thirteenth partial group U13 becomes weaker than the refractive power of the first lens group U1, making it difficult to reduce the effective diameter of the eleventh partial group U11 and the twelfth partial group U12. Miniaturization becomes difficult.

  If the lower limit of conditional expression (5) is exceeded, the positive refractive power of the thirteenth partial group U13 will become strong, making it difficult to correct spherical aberration, axial chromatic aberration, etc. at the telephoto end. More preferably, the numerical ranges of conditional expression (4) and conditional expression (5) are set as follows.

−1.4 <f12 / f11 <−0.8 (4a)
0.8 <f13 / f1 <1.1 (5a)

  Conditional expression (6) defines the thickness DL1 of the first lens unit U1 on the optical axis and the principal point interval e11 between the eleventh subgroup U11 and the twelfth subgroup U12 when focusing on an object at infinity. Yes. Conditional expression (7) defines the ratio of the principal point interval e12 between the twelfth partial group U12 and the thirteenth partial group U13 with respect to the thickness DL1. By satisfying conditional expressions (6) and (7), the zoom lens can be miniaturized and various aberrations can be corrected well. Here, the combined refractive power Φab of the a group and the b group whose principal point interval is e is

It is represented by When the signs of the refractive powers of the a-group and the b-group are different from each other, as is clear from Equation 4, after the interval e between the a-group and the b-group is narrowed, In order to maintain the combined refractive power Φab, it is necessary to increase the refractive powers Φa and Φb of the a group and the b group.

  If the distance between the principal points of the eleventh partial group U11 and the twelfth partial group U12 is larger than the upper limit of the conditional expression (6) and the object is focused on infinity, it is difficult to reduce the size of the zoom lens. When the distance between the principal points of the eleventh partial group U11 and the twelfth partial group U12 when the object is focused on an object at infinity exceeding the lower limit of the conditional expression (6) becomes smaller, the eleventh partial group U11 and the twelfth The refractive power of the subgroup U12 increases. As a result, it becomes difficult to correct distortion aberration, astigmatism, and aberration fluctuations accompanying focusing at the wide-angle end.

  If the distance between the principal points of the twelfth partial group U12 and the thirteenth partial group U13 when the upper limit of the conditional expression (7) is exceeded and the object is focused on infinity is increased, it is difficult to reduce the size of the zoom lens. If the lower limit of the conditional expression (7) is exceeded and the principal point interval between the twelfth partial group U12 and the thirteenth partial group U13 when focusing on an object at infinity is reduced, the positive value of the twelfth partial group U12 is accordingly increased. The refractive power and the positive refractive power of the thirteenth partial group U13 are increased. As a result, it becomes difficult to correct aberration variations accompanying focusing, spherical aberration, axial chromatic aberration, and the like at the telephoto end. More preferably, the numerical ranges of conditional expressions (6) and (7) should be set as follows.

-0.1 <e11 / DL1 <0.2 (6a)
0.2 <e12 / DL1 <0.4 (7a)

  Conditional expression (8) satisfies the condition of the first lens unit U1 when focusing on an object at infinity from the vertex of the lens surface on the image side of the first lens unit U1 with respect to the thickness DL1 on the optical axis of the first lens unit U1. The ratio of the distance Ok_1 to the image side principal point position is defined. Conditional expression (9) indicates that the distance O1_2 from the vertex on the object side lens surface of the second lens unit U2 to the object side principal point position of the second lens unit U2 with respect to the thickness DL2 on the optical axis of the second lens unit U2. The ratio is specified. By satisfying conditional expressions (8) and (9), various aberrations are favorably corrected while downsizing the zoom lens.

  If the actual distance between the first lens unit U1 and the second lens unit U2 increases beyond the upper limit of the conditional expression (8), it is difficult to reduce the size of the zoom lens. If the lower limit of conditional expression (8) is exceeded and the image side principal point position of the first lens unit U1 is excessively located on the object side, the refractive power of each lens in the thirteenth partial unit U13 becomes strong, and the entire system is small. It becomes difficult. Furthermore, it becomes difficult to correct spherical aberration, axial chromatic aberration and the like at the telephoto end.

  If the upper limit of the conditional expression (9) is exceeded and the object side principal point position of the second lens unit U2 is excessively positioned on the image side, the refractive power of each lens in the second lens unit U2 becomes strong, and accompanying zooming. Aberration variation increases, making it difficult to obtain good optical performance over the entire zoom range. If the actual distance between the first lens unit U1 and the second lens unit U2 increases beyond the lower limit of the conditional expression (9), it is difficult to reduce the size of the zoom lens. More preferably, the numerical ranges of conditional expressions (8) and (9) should be set as follows.

-0.30 <Ok_1 / DL1 <-0.05 (8a)
0.4 <O1_2 / DL2 <0.7 (9a)

  In the eleventh partial group U11 (first lens group U1), it is preferable to dispose a lens having a positive refractive power closest to the object side. According to this, it becomes easy to reduce the change in the image field due to focusing while reducing the size of the entire system.

  Here, by appropriately setting the lens configuration of the eleventh partial group U11, it is possible to reduce the change in the field of view accompanying focusing while reducing the size of the entire system, as shown in FIGS. ).

  As apparent from Equation 4, in order to increase the refractive power Φ12 of the twelfth partial group U12 while maintaining the combined refractive power Φ11_12 of the eleventh partial group U11 and the twelfth partial group U12, the eleventh partial group U11 And the principal point interval e11 of the twelfth partial group U12 may be narrowed. The movement amount Δx of the twelfth partial group U12 when focusing from an infinitely distant object to a short distance object increases as the refractive power of the twelfth partial group U12 is weakened.

  Therefore, in order to reduce the field change due to focusing, the refracting power of the twelfth partial group U12 is increased as shown in FIG. 16B with respect to FIG. It is necessary to narrow the principal point interval e11 between the group U11 and the twelfth partial group U12. In order to reduce the principal point interval e11 between the eleventh partial group U11 and the twelfth partial group U12 without causing lens interference between the eleventh partial group U11 and the twelfth partial group U12, the lens configuration of the eleventh partial group U11 is used. And the image side principal point of the eleventh partial group U11 may be set closer to the image plane side.

  Specifically, in the eleventh partial group U11, the image side principal point of the eleventh partial group U11 having a negative refractive power is effectively set on the image side by disposing a lens having a positive refractive power closest to the object side. can do.

  Conditional expression (10) defines the lens shape of the positive lens G1 closest to the object side in the eleventh subgroup U11. By satisfying conditional expression (10), the entire system is reduced in size, the change in the field of view accompanying focusing is reduced, and off-axis aberrations, particularly distortion, are corrected well at the wide-angle end. When the refractive power of the most object side positive lens G1 of the eleventh partial group U11 becomes weak, it becomes difficult to set the image side principal point of the eleventh partial group U11 to the image side, and the positive refractive power of the twelfth partial group U12 becomes small. Due to the shortage, it becomes difficult to reduce the change in the image field due to focusing.

  On the other hand, in the third-order aberration theory, the distortion aberration coefficient V is proportional to the first power of the incident height h of the axial paraxial ray and the third power of the incident height H of the pupil paraxial ray. As shown in FIG. 13A, the incident height Hw of the pupil paraxial ray at the wide-angle end becomes higher with the lens closest to the object in the eleventh subgroup U11. For this reason, in order to correct distortion well at the wide-angle end, it is necessary to appropriately set the lens shape of the positive lens G1 closest to the object side in the eleventh subgroup U11.

  Here, an object side lens surface of the positive lens G1 is defined as an R1 surface, and an image side surface is defined as an R2 surface. When the radius of curvature of the convex surface of the R1 surface of the positive lens G1 is increased, the incident angle to the R1 surface is decreased, and the barrel generated on the concave surface of the negative lens of the eleventh subgroup U11 having a high incident height Hw of the paraxial ray. It becomes difficult to cancel the distortion of the mold. As a result, it becomes difficult to correct barrel distortion at the wide-angle end.

  If the upper limit of conditional expression (10) is exceeded, the shape of the positive lens G1 has a small radius of curvature of the convex surface of the R1 surface and a large radius of curvature of the concave surface of the R2 surface. Therefore, the difference in the radius of curvature between the R1 surface and the R2 surface becomes large, so that the positive refractive power of the positive lens G1 becomes strong, and it becomes difficult to correct off-axis aberrations at the wide angle end. When the lower limit of conditional expression (10) is exceeded, the difference in the radius of curvature between the convex surface of the R1 surface and the concave surface of the R2 surface of the positive lens G1 becomes small. Therefore, it becomes difficult to position the object side principal point of the eleventh subgroup U11 on the image side, the lens diameter and the lens thickness of the positive lens G1 increase, and it becomes difficult to reduce the size of the eleventh subgroup U11.

  Further, since the positive refractive power of the twelfth partial group U12 is insufficient, it becomes difficult to reduce the field of view accompanying the downsizing and focusing of the first lens group U1. More preferably, the numerical range of conditional expression (10) is set as follows.

-9.5 <(R1 + R2) / (R1-R2) <-4.5 (10a)
It is preferable to have a lens having a positive refractive power on the most object side of the thirteenth partial group U13 and the second lens group U2. This facilitates the telephoto zoom lens and the miniaturization of the entire system. Here, it is easy to appropriately set the lens configurations of the first lens unit U1 and the second lens unit U2 to achieve telephoto zooming and downsizing of the entire system, as shown in FIGS. Explanation will be made using (B).

  By appropriately increasing the focal length f1 of the first lens unit U1, it is possible to increase the focal length of the entire system and to achieve telephoto zoom lens. However, if the main point interval L1 between the first lens unit U1 and the second lens unit U2 is increased and the actual interval between the first lens unit U1 and the second lens unit U2 is increased, it is difficult to reduce the size of the entire system.

  Therefore, by devising the lens configuration in the first lens unit U1 and the second lens unit U2, the image side principal point of the first lens unit U1 is further moved to the object side, and the object side principal point of the second lens unit U2 is changed. Set to the image plane side. And even if the main point interval L1 between the first lens unit U1 and the second lens unit U2 increases, it is important to achieve the downsizing of the entire system to maintain the actual interval between the first lens unit U1 and the second lens unit U2. It is.

  As shown in FIG. 17B with respect to FIG. 17A, in order to effectively set the image side principal point of the first lens unit U1 on the object side, the thirteenth partial group having a positive refractive power. The image side principal point of U13 may be set closer to the object side. Specifically, it is effective to dispose a lens having a positive refractive power on the most object side of the thirteenth partial group U13. Similarly, as shown in FIG. 17B with respect to FIG. 17A, in order to set the object side principal point of the second lens unit U2 closer to the image side, the most object side of the second lens unit U2 It is effective to dispose a lens having a positive refractive power at.

  Conditional expression (11) defines the ratio between the focal length of the second lens unit U2 and the focal length of the third lens unit U3. By satisfying conditional expression (11), the entire system can be reduced in size while achieving a high zoom ratio, and various aberrations are corrected well. When the lower limit of conditional expression (11) is exceeded and the negative refracting power of the second lens unit U2 becomes stronger (when the absolute value of the negative refracting power becomes larger), the aberration fluctuation associated with zooming becomes larger, and the entire zoom range. It becomes difficult to obtain good optical performance.

  If the lower limit of conditional expression (11) is exceeded and the negative refractive power of the second lens unit U2 becomes weaker (when the absolute value of the negative refractive power becomes smaller), the amount of movement of the second lens unit U2 due to zooming becomes smaller. It becomes large and it becomes difficult to reduce the size of the entire system while achieving a high zoom ratio. More preferably, the numerical range of conditional expression (11) is set as follows.

0.3 <| f2 / f3 | <0.7 (11a)
Conditional expression (12) defines the reciprocal of the lateral magnification β3w of the third lens unit U3 at the wide-angle end when the light beam enters from an object at infinity. By satisfying conditional expression (12), the emitted light beam from the third lens unit U3 becomes substantially afocal, so the number of constituent lenses of the fourth lens unit U4 is reduced, and the entire system can be downsized. It becomes easy. If the upper limit of conditional expression (12) is exceeded, the divergence of the emitted light from the third lens unit U3 becomes strong, and a lens unit having a strong positive refractive power is required for the fourth lens unit U4. Since the number of lenses constituting U4 increases, it is difficult to reduce the size of the entire system.

  When the lower limit of conditional expression (12) is exceeded, the convergence of the emitted light beam from the third lens unit U3 becomes strong. In order to make the emitted light beam from the third lens unit U3 a strong convergent light beam, it is necessary to increase the refractive power of the third lens unit U3, and the number of constituent lenses of the third lens unit U3 increases. It becomes difficult to reduce the size of U3. More preferably, the numerical range of conditional expression (12) is set as follows.

-1.30 <1 / β3w <2.00 (12a)
As described above, according to each embodiment, although the telephoto zoom lens is used, the entire system is small and light, and the change in the field due to focusing at the wide-angle end is reduced, so that from the wide-angle end to the telephoto end. A zoom lens having high optical performance in the entire zoom range can be obtained. In particular, it is possible to obtain a zoom lens having high optical performance over the entire zoom range of zoom ratio 3 to 4, wide angle end shooting angle of view 22 degrees to 35 degrees, and telephoto end angle of view 6 degrees to 12 degrees.

The outline of an imaging apparatus (television camera system) using the zoom lens of each numerical example as an imaging optical system will be described with reference to FIG. FIG. 18 is a schematic diagram of a main part of the imaging apparatus of the present invention. In FIG. 18, reference numeral 101 denotes any one zoom lens of Numerical Examples 1 to 6. Reference numeral 124 denotes a camera. The zoom lens 101 can be attached to and detached from the camera 124. An imaging apparatus 125 is configured by attaching the zoom lens 101 to the camera 124.

  The zoom lens 101 includes a first lens group F, a variable power lens group LZ, and an imaging lens group R. The first lens group F includes a focusing lens group. The zoom lens group LZ includes a lens group that moves on the optical axis for zooming and a lens group that moves on the optical axis for correcting image plane fluctuations accompanying zooming. SP is an aperture stop.

  Reference numerals 114 and 115 denote drive mechanisms such as helicoids and cams for driving the first lens group F and the variable power lens group LZ in the optical axis direction, respectively. Reference numerals 116 to 118 denote motors (drive means) that electrically drive the drive mechanisms 114 and 115 and the aperture stop SP. Reference numerals 119 to 121 denote detectors such as encoders, potentiometers, or photosensors for detecting positions on the optical axis of the first lens group F and the variable power lens group LZ and the aperture diameter of the aperture stop SP.

In the camera 124, 109 is a glass block corresponding to an optical filter or color separation prism in the camera 124, and 110 is a solid-state imaging device (photoelectric conversion device) such as a CCD sensor or a CMOS sensor that receives a subject image formed by the zoom lens 101. ). Reference numerals 111 and 122 denote CPUs that control various types of driving of the camera 124 and the zoom lens body 101. Thus, by applying the zoom lens of the present invention to a television camera, an imaging device having high optical performance is realized.

Numerical examples 1 to 6 corresponding to the first to sixth embodiments of the present invention are shown below. In each numerical example, i indicates the order of the surfaces from the object side, r _i is the radius of curvature of the i-th surface from the object side, d _i is the i-th and i + 1-th distance from the object side, nd _i and νd _i are the refractive index and Abbe number of the i-th optical member.

  The focal length, the F number, and the angle of view (degree) indicate when the object is focused on infinity. BF is the back focus, and is indicated by the distance from the final lens surface to the image plane. Each lens group data represents the focal length of each lens group, the length on the optical axis (lens configuration length), the front principal point position, and the rear principal point position. Further, the portion where the interval d between the optical surfaces is (variable) changes during zooming, and the surface interval corresponding to the focal length is shown in the separate table.

  Table 1 shows the parameters based on the lens data of Numerical Examples 1 to 6 and the calculation results of the conditional expressions. Table 2 shows the corresponding values of Equations 1 to 3. Numerical Examples 1 to 6 satisfy all of the conditional expressions (1) to (12). Although the zoom lens is a telephoto type zoom lens, the entire system is small and light, and focusing at the wide-angle end is also performed. Changes in the field of view, and high optical performance is achieved over the entire zoom range.

  In Numerical Examples 1 to 6, the eleventh partial group U11 and the thirteenth partial group U13 have a positive lens closest to the object side, which is accompanied by the telephoto zoom lens, the miniaturization of the entire system, and focusing at the wide-angle end. Achieved reduction of field change. In Numerical Example 3, the second lens unit U2 has a positive lens closest to the object side, and in particular, the zoom lens is telephoto and downsized.

<Numerical Example 1>
Surface data surface number rd nd νd Effective diameter
1 65.731 5.19 1.80809 22.8 72.71
2 83.968 7.33 71.27
3 704.156 2.50 1.83481 42.7 71.13
4 165.923 4.67 69.59
5 -888.639 2.50 1.75500 52.3 69.53
6 132.829 3.25 69.22
7 209.414 2.50 1.72825 28.5 70.01
8 141.033 10.72 1.61800 63.3 70.53
9 -151.912 25.91 70.89
10 115.369 7.17 1.49700 81.5 70.48
11 1793.566 0.20 70.04
12 69.076 2.85 1.84666 23.8 67.37
13 45.198 0.67 62.86
14 45.926 12.16 1.62041 60.3 63.01
15 212.268 (variable) 62.06
16 -1599.963 1.20 1.78800 47.4 36.80
17 70.927 5.13 1.80809 22.8 35.62
18 -117.197 0.20 35.12
19 -237.198 1.20 1.72916 54.7 34.26
20 48.117 6.43 32.23
21 -42.722 1.20 1.72916 54.7 32.09
22 -4056.747 (variable) 32.95
23 130.535 4.36 1.58913 61.1 33.85
24 -83.901 0.20 34.02
25 -1055.517 4.70 1.49700 81.5 33.91
26 -44.706 1.20 1.83400 37.2 33.86
27 -108.537 (variable) 34.25
28 (Aperture) ∞ 0.80 33.71
29 37.266 5.42 1.60 300 65.4 33.52
30 107.500 6.96 32.47
31 48.486 7.63 1.61800 63.3 28.93
32 -75.152 1.37 26.77
33 -60.745 5.97 1.80809 22.8 25.18
34 -36.498 1.50 1.74950 35.3 23.15
35 26.068 15.13 22.24
36 1870.109 4.70 1.58913 61.1 28.24
37 -97.266 8.20 29.26
38 42.606 4.51 1.71736 29.5 32.73
39 76.521 32.16
Image plane ∞

Various data Zoom ratio 2.86
Wide angle Medium Telephoto focal length 70.00 118.30 200.00
F number 2.80 2.80 2.80
Half angle of view (degrees) 12.52 7.49 4.45
Image height 15.55 15.55 15.55
Total lens length 277.01 277.01 277.01
BF 44.72 44.72 44.72

d15 7.79 30.11 42.72
d22 40.59 25.71 1.50
d27 8.28 0.83 12.43

Entrance pupil position 152.20 233.98 315.02
Exit pupil position -74.11 -74.11 -74.11
Front principal point position 180.96 234.51 178.40
Rear principal point position -25.28 -73.58 -155.28

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -148.20 22.20 28.76 8.72
2 7 149.43 13.22 4.75 -3.43
3 10 117.48 23.05 -0.77 -15.04
4 16 -33.80 15.37 8.19 -3.08
5 23 90.00 10.46 2.14 -4.66
6 28 ∞ 0.00 0.00 0.00
7 29 102.10 61.40 21.31 -45.89

Focusing variable interval close (1.0m from image plane)
d6 27.66
d9 1.50

<Numerical Example 2>
Surface data surface number rd nd νd Effective diameter
1 64.274 5.27 1.80809 22.8 69.05
2 81.175 5.27 67.33
3 242.967 2.50 1.83481 42.7 67.18
4 93.798 7.54 64.79
5 -359.037 2.50 1.75500 52.3 64.76
6 203.945 10.00 64.78
7 328.182 2.50 1.72825 28.5 67.10
8 175.701 11.22 1.61800 63.3 67.33
9 -140.192 21.91 67.67
10 110.171 6.31 1.49700 81.5 62.61
11 2073.561 0.20 62.00
12 69.193 2.85 1.84666 23.8 59.13
13 45.925 0.37 56.05
14 46.366 10.62 1.62041 60.3 56.13
15 466.509 (variable) 55.34
16 -395.605 1.20 1.78800 47.4 33.32
17 70.612 4.65 1.80809 22.8 32.37
18 -104.174 0.20 31.94
19 -291.056 1.20 1.72916 54.7 31.08
20 49.270 5.43 29.50
21 -42.009 1.20 1.72916 54.7 29.37
22 485.661 (variable) 30.07
23 -296.265 3.14 1.58913 61.1 32.47
24 -124.705 0.20 33.11
25 109.107 6.64 1.49700 81.5 33.77
26 -40.176 1.20 1.83400 37.2 33.87
27 -67.949 (variable) 34.46
28 (Aperture) ∞ 1.00 34.07
29 41.097 5.75 1.60 300 65.4 33.91
30 152.446 3.95 32.85
31 42.062 8.00 1.60300 65.4 30.27
32 -97.079 1.24 27.92
33 -78.904 6.08 1.80809 22.8 26.49
34 -40.954 1.50 1.74950 35.3 24.21
35 25.428 13.86 22.08
36 7006.852 4.98 1.58913 61.1 27.01
37 -102.195 4.84 28.08
38 83.526 4.33 1.64769 33.8 29.95
39 2084.296 29.99
Image plane ∞

Various data Zoom ratio 2.86
Wide angle Medium Telephoto focal length 50.00 84.50 142.86
F number 2.60 2.60 2.60
Half angle of view (degrees) 17.28 10.43 6.21
Image height 15.55 15.55 15.55
Total lens length 269.04 269.04 269.04
BF 43.98 43.98 43.98

d15 2.61 25.71 38.83
d22 41.61 28.74 7.55
d27 11.19 0.96 9.04

Entrance pupil position 113.72 173.74 232.30
Exit pupil position -60.09 -60.09 -60.09
Front principal point position 139.70 189.63 179.07
Rear principal point position -6.02 -40.52 -98.87

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -129.83 23.07 25.61 5.12
2 7 167.99 13.72 6.07 -2.39
3 10 97.27 20.35 1.11 -11.63
4 16 -31.90 13.88 7.35 -2.65
5 23 90.00 11.18 4.76 -2.57
6 28 ∞ 0.00 0.00 -0.00
7 29 94.45 54.53 14.29 -41.85

Focusing variable interval close (1.0m from image plane)
d6 29.52
d9 2.39

<Numerical Example 3>
Surface data surface number rd nd νd Effective diameter
1 61.594 5.85 1.80518 25.4 71.72
2 78.568 8.28 69.95
3 656.502 2.50 1.80610 40.9 69.53
4 166.439 4.48 68.41
5 -1446.069 2.50 1.72916 54.7 68.38
6 109.746 4.02 68.29
7 196.721 2.50 1.72825 28.5 69.09
8 128.300 10.99 1.61800 63.3 69.60
9 -150.306 26.94 69.94
10 184.449 7.04 1.49700 81.5 69.20
11 -2970.795 0.20 68.69
12 65.418 2.85 1.84666 23.8 66.57
13 46.192 1.27 62.70
14 47.384 12.73 1.62041 60.3 63.00
15 153.977 (variable) 61.20
16 -1054.361 4.08 1.92286 18.9 34.42
17 -73.945 1.20 1.72916 54.7 33.87
18 59.349 4.88 32.08
19 -55.461 1.20 1.72916 54.7 32.03
20 902.210 (variable) 32.61
21 701.907 3.42 1.58913 61.1 32.96
22 -184.756 0.20 33.38
23 129.191 7.85 1.49700 81.5 33.72
24 -45.576 1.20 1.83400 37.2 33.79
25 -77.301 (variable) 34.20
26 (Aperture) ∞ 11.33 33.04
27 40.137 6.18 1.60 300 65.4 31.86
28 207.853 1.36 30.59
29 70.860 5.10 1.60 300 65.4 29.40
30 -86.607 1.24 28.26
31 -74.364 5.90 1.80809 22.8 26.96
32 -43.668 1.50 1.74950 35.3 25.09
33 31.717 13.19 24.04
34 -1112.710 4.68 1.58913 61.1 27.39
35 -128.894 7.94 28.21
36 97.362 4.75 1.84666 23.8 30.14
37 269.256 29.97
Image plane ∞

Various data Zoom ratio 2.86
Wide angle Medium Telephoto focal length 80.00 135.20 228.57
F number 3.20 3.20 3.20
Half angle of view (degrees) 11.00 6.56 3.89
Image height 15.55 15.55 15.55
Total lens length 307.41 307.41 307.41
BF 59.42 59.42 59.42

d15 11.21 40.12 54.91
d20 44.50 27.82 1.12
d25 12.90 0.66 12.57

Entrance pupil position 166.31 266.58 353.59
Exit pupil position -63.91 -63.91 -63.91
Front principal point position 194.42 253.58 158.58
Rear principal point position -20.58 -75.78 -169.15

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -149.20 23.61 33.29 11.18
2 7 145.47 13.49 4.76 -3.59
3 10 141.48 24.09 -1.81 -16.74
4 16 -39.60 11.36 5.50 -2.72
5 21 90.00 12.67 4.38 -4.00
6 26 ∞ 0.00 0.00 -0.00
7 27 133.92 51.86 9.12 -39.78

Focusing variable interval close (1.0m from image plane)
d6 29.46
d9 1.50

<Numerical Example 4>
Surface data surface number rd nd νd Effective diameter
1 65.540 6.31 1.80809 22.8 73.15
2 94.797 3.03 71.37
3 152.149 2.50 1.83400 37.2 71.14
4 90.213 7.78 67.84
5 -665.742 2.50 1.83481 42.7 67.79
6 129.755 3.77 67.73
7 185.887 2.50 1.80518 25.4 68.89
8 115.385 10.47 1.61800 63.3 69.24
9 -196.706 28.95 69.57
10 89.259 8.51 1.49700 81.5 71.15
11 711.283 0.20 70.64
12 66.853 2.85 1.84666 23.8 67.75
13 45.442 0.66 63.23
14 46.139 12.52 1.62041 60.3 63.33
15 244.518 (variable) 62.29
16 308.956 1.20 1.77250 49.6 47.89
17 68.337 7.36 1.84666 23.8 45.90
18 -140.010 0.20 45.16
19 -179.496 1.20 1.69680 55.5 44.17
20 45.818 9.36 39.85
21 -46.363 1.20 1.69680 55.5 39.73
22 169.670 (variable) 41.00
23 169.120 7.23 1.58313 59.4 41.51
24 -57.870 0.20 41.94
25 63.553 9.84 1.59201 67.0 41.08
26 -63.282 1.50 1.84666 23.8 40.05
27 -805.517 (variable) 39.26
28 (Aperture) ∞ 4.71 29.54
29 -35.559 1.20 1.80610 33.3 28.93
30 125.095 2.61 1.92286 18.9 29.98
31 -595.902 4.24 30.24
32 -106.036 4.27 1.59522 67.7 31.18
33 -38.109 8.93 31.75
34 255.536 4.69 1.59522 67.7 30.97
35 -56.163 26.23 31.21
36 -38.043 1.50 1.80610 33.3 27.23
37 -206.415 3.12 1.92286 18.9 28.14
38 -64.120 28.63
Image plane ∞

Various data Zoom ratio 2.86
Wide angle Medium telephoto focal length 70.00 118.09 200.00
F number 2.80 2.80 2.80
Half angle of view (degrees) 12.52 7.50 4.45
Image height 15.55 15.55 15.55
Total lens length 285.02 285.02 285.02
BF 43.99 43.99 43.99

d15 2.00 12.70 20.78
d22 44.69 23.05 0.99
d27 1.00 11.94 25.92

Entrance pupil position 162.88 214.36 315.32
Exit pupil position -52.66 -52.66 -52.66
Front principal point position 182.18 188.16 101.44
Rear principal point position -26.01 -74.11 -156.01

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -156.40 22.12 31.70 11.62
2 7 172.58 12.97 3.88 -4.07
3 10 98.77 24.74 0.26 -15.18
4 16 -33.80 20.52 12.76 -2.72
5 23 50.00 18.77 2.98 -8.67
6 28 ∞ 0.00 0.00 -0.00
7 29 609.17 56.78 84.53 51.91

Focusing variable interval close (1.0m from image plane)
d6 31.23
d9 1.50

<Numerical example 5>
Surface data surface number rd nd νd Effective diameter
1 64.431 6.75 1.80809 22.8 73.68
2 90.638 5.88 72.11
3 251.203 2.50 1.83400 37.2 71.74
4 113.580 7.03 69.89
5 -1173.716 2.50 1.81600 46.6 69.80
6 118.897 4.20 69.63
7 236.710 2.50 1.72825 28.5 70.43
8 153.195 10.40 1.61800 63.3 71.02
9 -154.541 27.74 71.41
10 171.266 6.72 1.49700 81.5 72.01
11 -726.185 0.20 71.75
12 61.167 2.85 1.84666 23.8 68.85
13 45.527 1.37 64.68
14 46.393 12.82 1.49700 81.5 64.97
15 215.962 (variable) 64.08
16 493.240 1.20 1.77250 49.6 33.39
17 38.274 6.62 1.80610 33.3 31.95
18 -97.068 0.20 31.32
19 -187.503 1.20 1.59201 67.0 30.46
20 38.783 5.92 28.17
21 -37.121 1.20 1.69680 55.5 27.97
22 -674.787 (variable) 28.47
23 -82.142 1.80 1.75500 52.3 28.79
24 115.179 2.47 1.84666 23.8 29.85
25 4220.071 (variable) 30.21
26 (Aperture) ∞ 1.00 30.68
27 117.400 3.72 1.60 300 65.4 31.62
28 -112.527 0.20 31.87
29 66.298 4.06 1.60 300 65.4 32.20
30 -228.168 0.20 32.01
31 55.954 5.77 1.48749 70.2 31.15
32 -63.408 1.40 2.00069 25.5 30.49
33 76.807 0.20 29.80
34 32.403 7.58 1.62041 60.3 30.05
35 -234.952 18.55 28.92
36 -35.335 0.90 1.88300 40.8 20.64
37 32.456 6.13 1.92286 18.9 21.24
38 -68.831 1.39 21.67
39 -350.265 0.90 1.81600 46.6 21.54
40 24.679 4.01 21.52
41 28.245 5.79 1.51633 64.1 26.22
42 -88.430 8.01 26.46
43 35.489 4.60 1.51823 58.9 27.43
44 -270.201 3.02 27.08
45 -30.567 1.25 2.00069 25.5 26.99
46 -54.568 27.76
Image plane ∞

Various data Zoom ratio 4.00
Wide angle Medium Telephoto focal length 70.00 140.00 280.00
F number 3.80 3.80 3.80
Half angle of view (degrees) 12.52 6.34 3.18
Image height 15.55 15.55 15.55
Total lens length 300.02 300.02 300.02
BF 44.71 44.71 44.71

d15 5.80 36.87 58.83
d22 47.00 11.25 2.73
d25 9.79 14.47 1.03

Entrance pupil position 159.06 253.72 340.16
Exit pupil position -60.50 -60.50 -60.50
Front principal point position 182.48 207.43 -125.00
Rear principal point position -25.29 -95.29 -235.29

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -152.35 24.65 35.97 12.70
2 7 158.81 12.90 4.85 -3.12
3 10 130.78 23.95 -0.22 -15.99
4 16 -39.00 16.34 10.23 -1.74
5 23 -116.37 4.27 -0.04 -2.40
6 26 ∞ 0.00 0.00 -0.00
7 27 40.60 77.67 -5.08 -64.21

Focusing variable interval close (1.0m from image plane)
d6 30.43
d9 1.50

<Numerical Example 6>
Surface data surface number rd nd νd Effective diameter
1 64.555 6.22 1.80809 22.8 73.36
2 91.018 5.66 71.86
3 319.524 2.50 1.81600 46.6 71.70
4 106.580 6.52 69.16
5 -1317.702 2.50 1.83400 37.2 69.11
6 136.122 3.51 68.55
7 245.747 2.50 1.72825 28.5 69.03
8 154.423 10.76 1.61800 63.3 69.67
9 -132.213 24.35 70.10
10 93.456 8.21 1.49700 81.5 70.06
11 1020.609 0.20 69.54
12 60.068 2.85 1.84666 23.8 66.06
13 41.729 0.42 61.18
14 42.093 11.32 1.62041 60.3 61.25
15 112.416 (variable) 59.94
16 455.929 1.20 1.77250 49.6 37.94
17 57.296 5.92 1.80518 25.4 36.48
18 -116.160 0.20 35.87
19 -168.600 1.20 1.69680 55.5 35.11
20 44.947 6.99 32.54
21 -40.220 1.20 1.69680 55.5 32.38
22 741.329 (variable) 33.26
23 102.569 2.00 1.83400 37.2 34.23
24 46.831 5.46 1.49700 81.5 34.35
25 -241.232 (variable) 34.70
26 96.123 4.36 1.58913 61.1 35.34
27 -136.278 (variable) 35.38
28 (Aperture) ∞ 3.37 33.56
29 34.945 5.37 1.60 300 65.4 32.67
30 140.612 2.00 31.66
31 67.167 4.16 1.61800 63.3 29.96
32 -116.042 1.50 29.11
33 -92.915 6.10 1.80809 22.8 27.42
34 -45.441 1.50 1.74950 35.3 25.12
35 25.415 19.47 22.37
36 55.883 3.64 1.58913 61.1 30.36
37 178.769 11.77 30.45
38 110.498 4.09 1.71736 29.5 32.52
39 1162.452 32.44
Image plane ∞

Various data Zoom ratio 2.86
Wide angle Medium Telephoto focal length 70.00 118.32 200.00
F number 2.80 2.80 2.80
Half angle of view (degrees) 12.52 7.49 4.45
Image height 15.55 15.55 15.55
Total lens length 277.00 277.00 277.00
BF 43.99 43.99 43.99

d15 3.53 26.93 38.04
d22 38.71 23.18 1.50
d25 2.41 3.32 0.20
d27 9.36 0.57 14.26

Entrance pupil position 149.95 238.81 317.28
Exit pupil position -80.20 -80.20 -80.20
Front principal point position 180.50 244.40 195.19
Rear principal point position -26.01 -74.33 -156.01

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 -143.15 23.40 31.32 9.91
2 7 145.89 13.26 5.38 -2.81
3 10 116.17 23.00 -3.99 -17.59
4 16 -33.80 16.71 9.81 -2.60
5 23 332.25 7.46 0.64 -4.13
6 26 95.97 4.36 1.14 -1.62
7 28 ∞ 0.00 0.00 -0.00
8 29 123.19 59.60 28.19 -37.76

Focusing variable interval close (1.0m from image plane)
d6 26.36
d9 1.50

U1 1st lens group U1 U2 2nd lens group U2 U3 3rd lens group U3
U4 4th lens group U4 U5 5th lens group U11 11th partial group U12 12th partial group U13 13th partial group UM Intermediate lens group UR Rear lens group

Claims (12)

In order from the object side to the image plane side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves for zooming , and a lens group that moves for zooming A zoom lens composed of an intermediate lens group having at least one lens, and a rear lens group that has a positive refractive power that does not move for zooming,
The first lens group is an eleventh sub-group having a negative refractive power that does not move for focusing, and has a positive refractive power that moves from the object side to the image plane side for focusing from an infinite object to a close object . 12 subgroup, for focusing consists thirteenth subgroup of positive refractive power and does not move, the focal length of the zoom lens at the wide angle end fw, the focal length of the first lens group f1, the second The focal length of 12 subgroups is f12 , the thickness on the optical axis of the first lens group is DL1, the thickness on the optical axis of the second lens group is DL2, and the object when focused on an infinite object The distance from the image-side lens surface vertex of the first lens group to the image-side principal point of the first lens group is Ok_1, and the object-side principal of the second lens group from the object-side lens surface vertex of the second lens group. the distance to the point as a O1_2,
0.5 <f12 / f1 <2.0
0.5 <f1 / fw <5.0
-0.5 <Ok_1 / DL1 <0.2
0.1 <O1_2 / DL2 <0.8
A zoom lens characterized by satisfying the following conditional expression: In order from the object side to the image plane side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves for zooming, and a lens group that moves for zooming A zoom lens composed of an intermediate lens group having at least one lens and a rear lens group that has a positive refractive power that does not move for zooming, and the first lens group is a negative lens that does not move for focusing. An eleventh sub-group of refractive power, a twelfth sub-group of positive refractive power that moves from the object side to the image plane side for focusing from an object at infinity to a near-distance object, and a positive positive refractive power that does not move for focusing The thirteenth partial group of
The first lens group has a positive lens closest to the object side,
The focal length of the zoom lens at the wide angle end is fw, the focal length of the first lens group is f1, and the focal length of the twelfth partial group is f12.
0.5 <f12 / f1 <2.0
0.5 <f1 / fw <5.0
A zoom lens characterized by satisfying the following conditional expression: The radius of curvature of the lens surface on the object side of the most object side of the positive lens in the first lens group R1, and the radius of curvature of the lens surface on the image side of the positive lens R2,
-11.0 <(R1 + R2) / (R1-R2) <-2.0
The zoom lens according to claim 2 , wherein the following conditional expression is satisfied. In order from the object side to the image plane side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves for zooming, and a lens group that moves for zooming A zoom lens composed of an intermediate lens group having at least one lens and a rear lens group that has a positive refractive power that does not move for zooming, and the first lens group is a negative lens that does not move for focusing. An eleventh sub-group of refractive power, a twelfth sub-group of positive refractive power that moves from the object side to the image plane side for focusing from an object at infinity to a near-distance object, and a positive positive refractive power that does not move for focusing The thirteenth partial group of
A positive lens on the most object side of the second lens group;
The focal length of the zoom lens at the wide angle end is fw, the focal length of the first lens group is f1, and the focal length of the twelfth partial group is f12.
0.5 <f12 / f1 <2.0
0.5 <f1 / fw <5.0
A zoom lens characterized by satisfying the following conditional expression: In order from the object side to the image plane side, a first lens unit having a positive refractive power that does not move for zooming, a second lens unit having a negative refractive power that moves for zooming, and a lens group that moves for zooming A zoom lens composed of an intermediate lens group having at least one lens and a rear lens group that has a positive refractive power that does not move for zooming, and the first lens group has a fixed negative power for focusing. An eleventh sub-group of refractive power, a twelfth sub-group of positive refractive power that moves from the object side to the image plane side for focusing from an object at infinity to a near-distance object, and a positive positive refractive power that does not move for focusing The thirteenth partial group of
The intermediate lens group includes a third lens group having a positive refractive power and a fourth lens group having a positive refractive power, and the rear lens group includes a fifth lens group having a positive refractive power,
The focal length of the zoom lens at the wide angle end is fw, the focal length of the first lens group is f1, and the focal length of the twelfth partial group is f12.
0.5 <f12 / f1 <2.0
0.5 <f1 / fw <5.0
A zoom lens characterized by satisfying the following conditional expression: It said intermediate lens group, a third lens group of positive or negative refractive power, the rear lens group, claims, characterized in that they are composed of the fourth lens unit having positive refractive power 1 to 4 The zoom lens of any one of these . As a f11 is a focal length of the eleventh subgroup,
−2.5 <f11 / f1 <−0.5
The zoom lens according to any one of claims 1 to 6, characterized by satisfying the following conditional expression. Wherein the focal length of the 11 subgroup f11, and the f13 the focal length of the first 13 partial group,
−1.5 <f12 / f11 <−0.5
0.3 <f13 / f1 <1.5
The zoom lens according to any one of claims 1 to 7, characterized by satisfying the following conditional expression. The thickness of the first lens group on the optical axis is DL1, and when the object is focused on an object at infinity, the principal point interval between the eleventh and twelfth group is e11, and the object at infinity is focused. the main point interval between the 13th partial group and the twelfth subgroup of time is set to e12,
−0.3 <e11 / DL1 <0.4
0.05 <e12 / DL1 <0.60
The zoom lens according to any one of claims 1 to 8, characterized by satisfying the following conditional expression. The thirteenth subgroup, zoom lens according to any one of claims 1 to 9, characterized in that it has a positive lens on the most object side. The focal length of the second lens group f2, the focal length of the third lens group f3, as a β3w the lateral magnification of the third lens group at the wide-angle end when focusing on an object at infinity,
0.2 <| f2 / f3 | <0.8
−1.40 <1 / β3w <2.10
The zoom lens according to claim 5, wherein the following conditional expression is satisfied. A zoom lens according to any one of claims 1 to 11,
And an image sensor that receives an image formed by said zoom lens,
An imaging device comprising: