JP6564208B2 - Zoom lens and imaging apparatus having the same - Google Patents

Description

  The present invention relates to a zoom lens and an image pickup apparatus having the same, and is suitable for a broadcast television, a movie television camera, a video camera, and the like in which a fluctuation amount of a focus position due to a manufacturing error or a temperature change is well corrected.

  Zoom lenses used for television shooting, movie shooting, and the like are generally used to correct a focus lens group for focusing, a variator for zooming, and image plane variation accompanying zooming in order from the object side to the image side. It has a variable power lens group including a compensator and an imaging lens group for imaging. In some broadcast lenses, the extender unit is arranged in the imaging lens group in a switchable state.

  Then, when focusing on the subject, manual focus for driving the focus lens group in the optical axis direction is performed by mechanical transmission of manual operation or electrical drive according to the manual operation.

  This is because, in television shooting and movie shooting, not only focusing on the subject but also focusing on the intention of the photographer is often used as a video effect. is there.

  Also, since a high-speed zooming operation is required in sports broadcasting or studio photography, a zoom cam mechanism in which the variable power lens group moves in the optical axis direction by the rotation of a cam cylinder is generally used.

  In the zoom lens driven by the manual focus and zoom cam mechanism as described above, there is a problem that the focus position fluctuates in the intermediate zoom range due to manufacturing variations such as the refractive index and interval of the variable power lens group and temperature changes.

  Further, there is a problem that the focus position varies depending on changes in spherical aberration when the diaphragm is opened and when it is stopped, changes in spherical aberration due to the position of the focus lens, switching of the extender, posture, and the like.

  In order to solve the above-described problems, it is necessary to suppress manufacturing variations and perform precise assembly adjustment. However, with the recent spread of high-definition cameras, the resolution is higher than that of conventional HD cameras, and the depth of focus. Therefore, it has become difficult to keep the above-described variation in the focus position within the range of the depth of focus.

  In order to cope with such a problem, for example, Patent Document 1 proposes a method of driving the following master lens group (imaging lens group). At the time of assembling the lens, fluctuations in the focus position due to changes in the zoom position, aperture position, and extender switching state are obtained in advance. When the zoom position, aperture position, and extender switching state change when the lens is used, the amount of focus position deviation is obtained from a lookup table or a calculation formula based on the change. In this method, the master lens group (imaging lens group) is driven so as to cancel the fluctuation amount.

JP-A-10-186209

  However, Patent Document 1 does not disclose any specific lens arrangement and configuration for realizing high-speed zooming operation and good optical performance while correcting the variation of the focus position. Further, there has been a problem that correction of variation in the focus position with respect to the change in the focusing position, temperature change, and posture is not taken into consideration.

For example, an object of the present invention is to provide a zoom lens that is advantageous in correcting a variation in focus position.

A focusing lens group which moves for focusing, two or more variable power lens unit which moves for the arranged on the image side of the focusing lens group and zooming, a stop, a relay lens group does not move for zooming a zoom lens having bets, the two or more lens group or the relay lens group, the focal position due to one or more factors including the attachment and detachment of the extender group as a sub-lens group in the relay lens group wherein the correction unit as lens group or sub lens group moves in order to correct fluctuation of a driving means for driving the correction group, wherein to compensate for variations in the focus position due to the one or more factors and control means for controlling the driving means, the maximum moving amount of the correcting unit and Mc, the for correcting the variation of the focus position The maximum amount of movement of the positive group and Mb, the correction group and ΔSk the maximum change in the imaging position when moved by the maximum moving amount Mb, zooming lens group included in the two or more lens group The maximum movement amount of M
0.001 <Mc / Mm <0.3
0.3 <| ΔSk | / Mb <3.0
The following expression is satisfied.

  Further objects and other features of the present invention will be made clear by the preferred embodiments described below with reference to the accompanying drawings.

According to the present invention, for example, it is possible to provide an advantageous zoom lens for correcting the variation of the focus position.

It is sectional drawing at the time of a wide angle end of Example 1 at the time of infinity focusing. (A), (B), (C) are aberration diagrams at the wide-angle end, the focal length of 65.53 mm, and the telephoto end when focusing on an object distance of infinity according to Example 1. FIG. 1 is a schematic diagram of a main part of Example 1. FIG. It is sectional drawing in the time of the wide angle end of Example 2 at the time of infinity focusing. (A), (B), and (C) are aberration diagrams at the wide-angle end, the focal length of 84.98 mm, and the telephoto end when the object distance is focused at infinity and when the correction lens unit is fully extended. FIG. 6 is a schematic diagram of a main part of a second embodiment. It is sectional drawing in the time of the wide angle end of Example 3 at the time of infinity focusing. (A), (B), (C) is an aberration diagram at the wide-angle end, the focal length of 189.61 mm, and the telephoto end when an object distance of 13 m is in focus according to Example 3. FIG. FIG. 6 is a schematic diagram of a main part of a third embodiment. It is sectional drawing in the time of the wide angle end of Example 4 at the time of infinity focusing. (A), (B), and (C) are aberration diagrams at the wide-angle end, the focal length of 20.67 mm, and the telephoto end when focusing on an object distance of infinity according to Example 4. FIG. FIG. 6 is a schematic diagram of a main part of a fourth embodiment. It is the schematic of a zoom cam mechanism.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a lens cross-sectional view at the time of focusing on an object at infinity at the wide angle end according to Numerical Embodiment 1 as Embodiment 1 of the present invention. 2A, 2B, and 2C are longitudinal aberration diagrams when focusing on an object at infinity at the wide-angle end, the focal length of 65.53 mm, and the telephoto end according to Numerical Example 1. FIG.

  In the longitudinal aberration diagram, spherical aberration indicates e-line (solid line) and g-line (dotted line). Astigmatism indicates the e-line meridional image plane (dotted line) and the sagittal image plane (solid line). The lateral chromatic aberration is represented by the g-line (dotted line). Fno represents an F number, and ω represents a shooting half angle of view. In the longitudinal aberration diagram, spherical aberration is 0.4 mm, astigmatism is 0.4 mm, distortion is 5%, and chromatic aberration of magnification is 0.05 mm.

  The zoom lens shown in Embodiment 1 will be specifically described with reference to FIG.

  In FIG. 1, U1 is a lens unit having a positive refractive power that does not move for zooming. U2 is a variator having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving monotonically on the optical axis toward the image plane side. U3 is a compensator having a positive refractive power, and moves on the optical axis from the image side to the object side in order to correct image plane fluctuations accompanying zooming. SP is an aperture, and U4 is a front relay lens group. U5 is an equal-magnification lens group, and either an extender lens group (not shown) or an equal-magnification lens group is arranged on the optical axis by a switching mechanism. U6 is a rear relay lens group. P is a color separation optical system, and I is an imaging surface. U1 is further composed of U11 having a negative refractive power, U12 having a positive refractive power, and U13 having a positive refractive power. The U12 and U13 are moved closer to each other at different ratios from the image side to the object side. Focus on a distance object.

In the first exemplary embodiment, the correction lens unit is the same as the front relay lens unit U4, and moves on the optical axis in order to correct the variation in the focus position.
FIG. 3 shows the configuration of an imaging system that is Embodiment 1 of the present invention.

  In the figure, reference numeral 1 denotes a focus lens group. Reference numeral 2 denotes a zoom lens group, which includes a lens group 2a that moves on the optical axis and zooms, and 2b that corrects an image plane that varies with zooming. Reference numeral 3 denotes an aperture stop. Reference numeral 4 denotes a front relay lens group, and 5 denotes an extender lens group, which includes an equal-magnification lens group 5a and an extender lens group 5b that shifts the focal length to the telephoto side, and either one of the lens groups is arranged on the optical axis. The Reference numeral 6 denotes a rear relay lens. In the first embodiment, the front relay lens group 4 functions as a correction lens group, and moves in the optical axis direction in order to correct a variation in focus position. As described above, in this embodiment, each element 1 to 6 constitutes a zoom lens. Reference numeral 7 denotes an image sensor that receives light from the zoom lens and is disposed in an image pickup apparatus to which the zoom lens according to the present invention is attached. Reference numeral 8 denotes a video signal processing circuit, which receives a video signal based on a signal from the image sensor 7. It has gained. Reference numeral 9 denotes a drive unit for the focus lens group 1, which drives the focus lens group 1 in the optical axis direction by a mechanism such as a helicoid or a cam. Reference numeral 10 denotes a drive unit for the variable power lens group 2, which drives the variable power lens group 2 in the optical axis direction by a cam mechanism as shown in FIG. Reference numeral 11 denotes a drive unit that adjusts the aperture diameter of the aperture stop 3. Reference numeral 12 denotes a driving unit for the correction lens group. Reference numeral 13 denotes switching means for the extender lens group 5. Reference numeral 14 denotes zoom position detecting means for detecting the zoom position of the variable magnification lens group 2. Reference numeral 15 denotes temperature detection means for detecting the temperature. Reference numeral 22 denotes correction lens group position detection means. Reference numeral 16 denotes a calculation unit, which performs calculations for controlling various types of driving of the entire zoom lens. Reference numeral 17 denotes a storage unit that stores the amount of change in focus position caused by a change in zoom position and a change in temperature.

  In the first embodiment, the variation amount of the focus position caused by the change of the zoom position and the temperature change is stored in the storage unit 17 at the time of product assembly adjustment. Then, the calculation unit 16 selects the variation amount of the focus position stored in the storage unit 17 based on signals from the zoom position detection unit 14 and the temperature detection unit 15 and inputs the selected variation amount to the drive unit 12 of the correction lens group. Then, the correction lens group driving unit 12 moves the correction lens group 4 in the optical axis direction based on the signal from the calculation unit 16 to correct the variation amount of the focus position.

The zoom lens according to the present invention includes a focus lens group that moves during a manual focusing operation, and at least two or more lenses that are disposed on the image side of the focus lens group and move on the optical axis by a cam mechanism for zooming. The zoom lens unit includes a zoom lens unit including a lens group, a stop, and a relay lens unit that is fixed during zooming for imaging. The zoom lens of the present invention corrects at least one focus position change among focus position changes caused by a change in zoom position, a change in position of the focus lens group, a change in temperature, a change in aperture position, and a change in posture. Therefore, a correction lens group that moves in the optical axis direction is provided, and the correction lens group is disposed in the variable power lens group or in the relay lens group. The maximum movement amount of the correction lens group is Mc, the maximum movement amount for correcting the focus position fluctuation is Mb, the maximum change amount of the imaging position when the correction lens group moves Mb is ΔSk, When the maximum movement amount of the lens unit in the double lens unit is Mm, the following conditional expression is satisfied.
0.001 <Mc / Mm <0.3 (1)
0.3 <| ΔSk | / Mb <3.0 (2)

  Conditional expression (1) defines a range of the ratio of the maximum movement amount of the correction lens group to the maximum movement amount of the lens group in the variable magnification lens group, thereby performing high-speed zoom operation while favorably correcting the variation of the focus position. Stipulates conditions for achieving high optical performance.

  Here, the change in posture refers to a posture (direction, angle) with respect to the vertical direction (gravity direction) in the optical axis direction, which is the driving direction of the movable lens group in the zoom lens, in the present specification.

  In order to realize a high-speed zoom operation as described above, the variable power lens group is driven in the optical axis direction at high speed by the rotation of the cam barrel. If the driving of the correction lens group does not follow the driving of the variable power lens group at high speed, an image with a sense of incongruity that is in focus while being delayed at the time of shooting will be obtained. The correction lens group includes, for example, a stepping motor and a rack engaged with a feed screw that is an output shaft of the motor, and is driven in the optical axis direction. Therefore, if the movement amount of the correction lens group becomes too large, It takes time to reach the drive position. In addition, if the amount of movement of the correction lens group becomes too large, variations in spherical aberration, astigmatism, and chromatic aberration become large, and high optical performance cannot be achieved. On the contrary, if the movement amount of the correction lens becomes too small, it becomes impossible to correct the focus position deviation due to the zoom position, the temperature change and the like as described above. From the above, in order to achieve high-speed zoom operation and high optical performance while satisfactorily correcting the variation in focus position, the ratio of the maximum movement amount of the correction lens group to the maximum movement amount of the lens group in the variable magnification lens group Must be set to an appropriate range.

  If the upper limit of conditional expression (1) is exceeded, the movement amount Mc of the correction lens group with respect to the maximum movement amount Mm of the lens group in the variable power lens group becomes too large, and it is difficult to follow the driving speed of the variable power lens group. It becomes. In addition, the aberration fluctuation due to the movement of the correction lens group becomes too large, and it becomes difficult to maintain high optical performance.

  If the lower limit of conditional expression (1) is exceeded, the driving amount Mc of the correction lens group with respect to the maximum movement amount Mm of the unit in the variable power lens group becomes too small, and the fluctuation of the focus position cannot be corrected sufficiently.

More preferably, conditional expression (1) is preferably set as follows.
0.001 <Mc / Mm <0.26 (1a)

  Conditional expression (2) defines the range of the ratio of the maximum displacement amount of the imaging position to the maximum movement amount for correcting the fluctuation of the focus position of the correction lens group, thereby favorably correcting the fluctuation of the focus position. It defines the conditions for achieving high-speed zoom operation and high optical performance.

  If the upper limit of the conditional expression (2) is exceeded, the change ΔSk of the imaging position with respect to the movement Mb for correcting the variation in the focus position of the correction lens group becomes too large, and the focus position changes due to the minute change of the correction lens group. Will occur. Further, in order to suppress a minute change of the correction lens group, the stopping accuracy of the stepping motor becomes too high.

  When the lower limit of the conditional expression (2) is exceeded, the change ΔSk in the imaging position with respect to the movement Mb for correcting the change in focus position of the correction lens group becomes too small, and the correction for correcting the change in focus position. The amount of movement of the lens group becomes too large, making it difficult to follow the driving speed of the variable power lens group. In addition, the aberration fluctuation due to the movement of the correction lens group becomes too large, and it becomes difficult to maintain high optical performance.

More preferably, conditional expression (2) is preferably set as follows.
0.45 <| ΔSk | / Mc <2.0 (2a)

Further, in the present invention, it is preferable that the following condition is satisfied, where Fno is the open F number of the zoom lens, δ is the allowable circle of confusion of the imaging apparatus, and D is the depth of focus.
D = Fno × δ
1.0 <Mb / D <300.0 (3)

  Conditional expression (3) defines the range of movement of the correction group for correcting the focus position fluctuation, thereby achieving high-speed zoom operation and high optical performance while favorably correcting the focus position fluctuation. The conditions are specified.

  If the upper limit of conditional expression (3) is exceeded, the maximum correction amount Mb of the correction lens group with respect to the focal depth D becomes too large, and it becomes difficult to follow the drive speed of the variable power lens group. In addition, the aberration fluctuation due to the movement of the correction lens group becomes too large, and it becomes difficult to maintain high optical performance.

  If the lower limit of conditional expression (3) is exceeded, the maximum movement amount Mb of the correction lens group with respect to the focal depth D becomes too small, and the effect of correcting the focus position deviation with respect to the movement of the correction lens group is lost.

More preferably, conditional expression (3) is preferably set as follows.
1.0 <Mb / D <100.0 (3a)

  Further, in the present invention, it is preferable that the correction lens group is disposed in the variable power lens group or on the image side of the variable power lens group. When the correction lens group is arranged on the object side of the variable power lens group, the displacement of the image formation position relative to the movement of the correction lens group is proportional to the square of the image magnification due to the change in the image magnification of the variable power lens group. Therefore, the focus position fluctuates due to a minute change of the correction lens group on the telephoto side. Alternatively, the driving amount becomes too large on the wide angle side, and it becomes difficult to follow the driving speed of the variable power lens group. In addition, the aberration fluctuation due to the movement of the correction lens group becomes too large, and it becomes difficult to maintain high optical performance.

  Furthermore, in the present invention, it is desirable that the correction lens group is composed of at least one lens and three or less lenses. When the correction lens group is composed of four or more lenses, the mass of the correction lens group increases, and high-speed drive control by the stepping motor becomes difficult.

  The zoom lens shown in Embodiment 1 will be specifically described with reference to FIG.

  In FIG. 1, U1 is a lens unit having a positive refractive power that does not move for zooming. U2 is a variator having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving monotonically on the optical axis toward the image plane side. U3 is a compensator having a positive refractive power, and moves on the optical axis from the image side to the object side in order to correct image plane fluctuations accompanying zooming. SP is an aperture, and U4 is a front relay lens group. U5 is an equal-magnification lens group, and one of the extender lens group (not shown) is disposed on the optical axis. U6 is a rear relay lens group. P is a color separation optical system, and I is an imaging surface. U1 is further composed of U11 having a negative refractive power, U12 having a positive refractive power, and U13 having a positive refractive power. The U12 and U13 are moved closer to each other at different ratios from the image side to the object side. Focus on a distance object.

  In the first exemplary embodiment, the front relay lens group U4 functions as a correction lens group, and moves in the optical axis direction in order to correct a change in focus position.

  U1 corresponds to the first surface to the tenth surface. U11 corresponds to the first surface to the fourth surface, and is composed of one negative lens and one positive lens. U12 corresponds to the fifth to eighth surfaces and is composed of two positive lenses. U13 corresponds to the ninth surface to the tenth surface and is composed of one positive lens. U2 corresponds to the 11th to 17th surfaces, and is composed of three negative lenses and one positive lens.

  U3 corresponds to the 18th to 26th surfaces, and is composed of one negative lens and four positive lenses. U4 corresponds to the 28th to 33rd surfaces, and is composed of two negative lenses and one positive lens. U5 corresponds to the 34th to 38th surfaces, and is composed of two negative lenses and one positive lens. U6 corresponds to the 39th to 48th surfaces and is composed of two negative lenses and four positive lenses. The correction lens group is composed of three negative lenses and two positive lenses.

  Aspheric surfaces are used for the 11th, 19th and 25th surfaces. It mainly corrects zoom fluctuations such as distortion and astigmatism.

  The open F number Fno of the zoom lens in Example 1 is 1.8. The permissible circle of confusion δ is 0.005 mm. Therefore, the focal depth D is 0.009 mm.

  In this embodiment, the maximum fluctuation amount of the focal position in the change of the zoom position is 5D. That is, it is set to 0.045 mm. The maximum fluctuation amount of the focal position in the temperature change is 20D. That is, it is 0.180 mm. As a result, a focus position change of 0.225 mm occurs. Therefore, the imaging position change amount ΔSk due to the movement of the correction lens group may be 0.225 mm. The change amount of the imaging position per 1 mm of the movement amount of the correction lens group is 0.910 mm. Accordingly, the maximum movement amount Mb for correcting the change in the imaging position of the correction lens group is 0.250 mm. Since the correction lens group is fixed during zooming, the maximum movement amount Mc of the correction lens group is equal to the maximum movement amount Mb for correcting the change in the imaging position, and Mc is 0.250 mm. The moving amount of U2, which has the largest moving amount in the variable power lens group, is 191.209 mm.

  Table 1 shows values corresponding to the conditional expressions of Example 1. Numerical Example 1 satisfies both of the conditional expressions, and realizes a zoom lens that can properly correct a zoom position change and a focus position shift due to a temperature change while realizing high-speed zooming operation and good optical performance. doing.

  The zoom lens shown in Embodiment 2 will be specifically described with reference to FIG.

  In FIG. 4, U1 is a lens unit having a positive refractive power that does not move for zooming. U2 is a variator having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving monotonically on the optical axis toward the image plane side. U3 is a second variator having a positive refractive power, and performs zooming from the wide angle end to the telephoto end by moving the optical axis from the image side to the object side. U4 is a compensator having a positive refractive power, and moves non-linearly on the optical axis to the object side in order to correct image plane fluctuations accompanying zooming. SP is a stop, and U5 is a front relay lens group. U6 is an equal-magnification lens group, and one of the extender lens group (not shown) is arranged on the optical axis. U7 is a rear relay lens group. P is a color separation prism optical system, and I is an imaging surface. U1 is further composed of U11 having a negative refractive power, U12 having a positive refractive power, and U13 having a positive refractive power. The U12 and U13 are moved closer to each other at different ratios from the image side to the object side. Focus on a distance object.

  In the second embodiment, the compensator U4 functions as a correction lens group and moves in the optical axis direction in order to correct the variation in the focus position.

  U1 corresponds to the first surface to the tenth surface. U11 corresponds to the first surface to the fourth surface, and is composed of one negative lens and one positive lens. U12 corresponds to the fifth to eighth surfaces and is composed of two positive lenses. U13 corresponds to the ninth surface to the tenth surface and is composed of one positive lens. U2 corresponds to the 11th to 17th surfaces, and is composed of three negative lenses and one positive lens.

  U3 corresponds to the 18th to 24th surfaces, and is composed of one negative lens and three positive lenses. U4 corresponds to the 25th to 26th surfaces and is composed of one positive lens. U5 corresponds to the 28th to 32nd surfaces, and is composed of two negative lenses and one positive lens. U6 corresponds to the 33rd to 39th surfaces and is composed of two negative lenses and two positive lenses. U7 corresponds to the 40th to 49th surfaces, and is composed of two negative lenses and four positive lenses. The correction lens group is composed of one positive lens.

  Aspheric surfaces are used for the 11th, 19th and 25th surfaces. It mainly corrects zoom fluctuations such as distortion and astigmatism.

  FIG. 6 shows the configuration of an imaging system according to the second embodiment of the present invention.

The zoom lens according to the second embodiment is configured by (A1) three variable power lens groups as compared with the first embodiment.
(A2) It has focus lens position detection means 18 for detecting the position of the focus lens group 1.
(A3) It has an aperture detection means 19 for detecting the aperture value of the aperture stop 3.
(A4) The change amount of the focus position due to the change of the position of the focus lens and the change of the aperture value is stored in the storage unit 17.
(A5) The first variator and the second variator are driven by a cam mechanism, and the compensator is driven by a stepping motor as a correction lens group.
Are different, and the other configurations are the same.

In addition, as a different form of the present embodiment,
(A5-2) The first variator, the second variator, and the compensator are driven by a cam mechanism to correct a change in focus position due to a change in zoom position, a change in temperature, a change in aperture value, and a change in focusing position. The correction lens group may be driven by a stepping motor inside the cylindrical cam.

  In the zoom lens according to the second embodiment, the change amount of the focus position due to the change of the zoom position, the change of the focus lens position, the temperature change, and the change of the aperture value is stored in the storage unit 17 during the assembly adjustment. Therefore, the calculation unit 16 is based on the signals (zoom position, focus position, temperature, aperture opening) detected by the zoom position detection unit 14, the focus lens position detection unit 18, the temperature detection unit 15, and the aperture detection unit 19. The fluctuation amount of the focus position stored in the storage unit 17 is read out and input to the drive unit 12 of the correction lens group. Then, the correction lens group driving unit 12 moves the correction lens group 4 on the optical axis based on the signal from the calculation unit 16 to correct the fluctuation amount of the focus position.

  Note that the correction information stored in the storage unit 17 may be information in a table format, or may be information obtained by calculating a variation amount with respect to various factors.

The open F number Fno of the zoom lens in Example 2 is 1.8.
As in the first embodiment, the allowable circle of confusion δ is 0.005 mm. Therefore, the focal depth D is 0.009 mm. The maximum fluctuation amount of the focal position in the change of the zoom position in the second embodiment is 5D, that is, 0.045 mm. The maximum fluctuation amount of the focal position in the temperature change is 20 D, that is, 0.180 mm. The maximum fluctuation amount of the focal position in the change of the aperture is 2D, that is, 0.018 mm. The maximum fluctuation amount of the focal position at the position of the focusing lens is 2D, that is, 0.018 mm. As a result, a focus position change of 0.261 mm may occur. Therefore, the imaging position change amount ΔSk due to the movement of the correction lens group may be 0.261 mm.

  The amount of change of the imaging position per 1 mm of the movement amount of the correction lens group is 0.583 (wide angle end) to 0.970 mm (telephoto end). Therefore, the maximum movement amount Mb for correcting the focus position change of the correction lens group is 0.448 mm. Further, the maximum movement amount for zooming of the correction lens group is 44.488 mm. Therefore, the maximum movement amount Mc of the correction lens group is 44.936 mm.

  The moving amount of U2 having the largest moving amount in the variable power lens group is 195.390 mm.

  Table 2 shows values corresponding to the conditional expressions of Example 2. Numerical Example 2 satisfies both of the conditional expressions. While realizing a high-speed zooming operation and good optical performance, the zoom position change, focus lens position change, temperature change, and aperture value change focus position. The zoom lens that can correct the fluctuation of the lens is realized.

  The zoom lens shown in Embodiment 3 will be specifically described with reference to FIG.

  In FIG. 7, U1 is a lens unit having a positive refractive power that does not move for zooming. U2 is a variator having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving monotonically on the optical axis toward the image plane side. U3 is a compensator having a positive refractive power, and moves on the optical axis from the image side to the object side in order to correct image plane fluctuations accompanying zooming. SP is an aperture, and U4 is a front relay lens group. U5 is an extender lens group, and one of the same-magnification lens group (not shown) is disposed on the optical axis. U6 is a rear relay lens group. P is a color separation prism optical system, and I is an imaging surface. U1 is further composed of U11 having a negative refractive power, U12 having a positive refractive power, and U13 having a positive refractive power. The U12 and U13 are moved closer to each other at different ratios from the image side to the object side. Focus on a distance object.

  In Example 3, some of the lens groups in the rear relay lens group U6 function as correction lens groups and move in the optical axis direction in order to correct variations in focus position.

  U1 corresponds to the first surface to the tenth surface. U11 corresponds to the first surface to the fourth surface, and is composed of one negative lens and one positive lens. U12 corresponds to the fifth to eighth surfaces and is composed of two positive lenses. U13 corresponds to the ninth surface to the tenth surface and is composed of one positive lens.

  U2 corresponds to the 11th to 17th surfaces, and is composed of three negative lenses and one positive lens. U3 corresponds to the 18th to 26th surfaces, and is composed of one negative lens and four positive lenses. U4 corresponds to the 28th to 32nd surfaces, and is composed of two negative lenses and one positive lens. U5 corresponds to the 33rd to 42nd surfaces, and is composed of three negative lenses and three positive lenses. U6 corresponds to the 43rd to 52nd surfaces, and is composed of two negative lenses and four positive lenses. The correction lens group corresponds to the forty-eighth surface to the forty-second surface, and is composed of one negative lens and two positive lenses.

  Aspheric surfaces are used for the 17th, 19th and 25th surfaces. It mainly corrects zoom fluctuations such as distortion and astigmatism.

  FIG. 9 shows a configuration of an imaging system according to the third embodiment of the present invention.

The zoom lens of Example 3 is different from that of Example 1 in that the (B1) extender lens group is disposed in the optical axis.
(B2) It has extender switching detection means 20 for detecting switching between the extender lens group and the equal-magnification lens group.
(B3) It has posture detecting means 21 for detecting the posture of the zoom lens.
(B4) The amount of change in the focus position due to the switching of the extender and the change in posture is stored in the storage unit 17.
Are different, and the other configurations are the same.

  In the zoom lens according to the third exemplary embodiment, the amount of change in the focus position due to the manufacturing error and temperature change of the variable power lens group, the switching of the extender lens group, and the change in posture is stored in the storage unit 17 in advance during assembly adjustment. Therefore, the calculation unit 16 is stored in the storage unit 17 by signals (zoom position, temperature, extender state, posture) from the zoom position detection unit 14, the temperature detection unit 15, the extender switching detection unit 20, and the posture detection unit 21. The amount of change in focus position is selected and input to the drive unit 12 of the correction lens group. Then, the correction lens group driving unit 12 moves the correction lens group 4 on the optical axis based on the signal from the calculation unit 16 to correct the fluctuation amount of the focus position.

  The open F number Fno of the zoom lens in Example 3 is 3.7. The allowable circle of confusion diameter δ is set to 0.005 mm as in the first embodiment. Therefore, the focal depth D is 0.019 mm.

  The maximum fluctuation amount of the focal position in the change of the zoom position in the third embodiment is 10D. That is, it is 0.190 mm. The maximum fluctuation amount of the focal position in the temperature change is 40D. That is, it is set to 0.760 mm. The maximum variation of the focal position due to switching of the extender lens group is 1D. That is, it is set to 0.019 mm. The maximum variation of the focal position depending on the posture is 10D. That is, it is 0.190 mm. As a result, a focus position change of 1.159 mm occurs. Therefore, the imaging position change amount ΔSk due to the movement of the correction lens group may be 1.159 mm.

  The change amount of the imaging position per 1 mm of the movement amount of the correction lens group is 0.954 mm. Therefore, the maximum movement amount Mb for correcting the change in the imaging position of the correction lens group is 1.215 mm. Since the correction lens group is fixed during zooming, the maximum movement amount Mc of the correction lens group is equal to the maximum movement amount Mb for correcting the change in the imaging position, and Mc is 1.215 mm. The moving amount of U2, which has the largest moving amount in the variable power lens group, is 173.572 mm.

  Table 3 shows values corresponding to the conditional expressions of Example 3. Numerical Example 3 satisfies both of the conditional expressions. While realizing high-speed zooming operation and good optical performance, the zoom position change, temperature change, extender lens group change, and focus position change due to attitude change can be achieved. A zoom lens that can correct fluctuations well is realized.

  The zoom lens shown in Example 4 will be specifically described with reference to FIG.

  In FIG. 10, U1 is a lens unit having a positive refractive power that does not move for zooming. U2 is a variator having a negative refractive power that moves during zooming, and performs zooming from the wide-angle end to the telephoto end by moving monotonically on the optical axis toward the image plane side. U3 is a second variator having negative refractive power, and moves non-linearly on the optical axis toward the object side. U4 is a compensator having a positive refractive power, and moves non-linearly on the optical axis to the object side in order to correct image plane fluctuations accompanying zooming. SP is a stop, and U5 is a front relay lens group. U6 is a rear relay lens group. An extender lens group (not shown) may be detachably disposed in the space between the front relay lens group U5 and the rear relay lens group U6. P is a color separation prism optical system, and I is an imaging surface. U1 further includes U11 having a negative refractive power and U12 having a positive refractive power. The U12 is focused from the image side to the object side to focus on a short-distance object.

  In the fourth embodiment, the compensator U4 functions as a correction lens group and moves in the optical axis direction in order to correct the variation in the focus position.

  U1 corresponds to the first surface to the eleventh surface. U11 corresponds to the first surface to the seventh surface, and is composed of two negative lenses and two positive lenses. U12 corresponds to the eighth surface to the eleventh surface, and is composed of two positive lenses.

  U2 corresponds to the twelfth to eighteenth surfaces, and is composed of two negative lenses and two positive lenses. U3 corresponds to the 19th to 21st surfaces, and is composed of one negative lens and one positive lens. U4 corresponds to the 22nd to 25th surfaces and is composed of two positive lenses. U5 corresponds to the 27th to 29th surfaces, and is composed of one negative lens and one positive lens. U6 corresponds to the 30th to 39th surfaces, and is composed of two negative lenses and four positive lenses. The correction lens group corresponds to the 22nd to 25th surfaces and is composed of two positive lenses.

  FIG. 12 shows the configuration of an imaging system according to the fourth embodiment of the present invention.

In Example 4, as compared with Example 1, (C1) the variable power lens group is composed of three groups.
(C2) The first variator and the second variator are driven by a cam mechanism, and the compensator is driven by a stepping motor as a correction lens group.
Are different, and the other configurations are the same.

  In the zoom lens according to the fourth exemplary embodiment, the amount of change in the focus position due to the change in the zoom position and the temperature is stored in the storage unit 17 in advance during assembly adjustment. Then, the calculation unit 16 selects the variation amount of the focus position stored in the storage unit 17 based on the signals (zoom position and temperature) from the zoom position detection unit 14 and the temperature detection unit 15, and the correction lens group driving unit 12. To enter. Then, the correction lens group driving unit 12 moves the correction lens group 4 on the optical axis based on the signal from the calculation unit 16 to correct the fluctuation amount of the focus position.

The open F number Fno of the zoom lens in Example 4 is 1.8.
The allowable circle of confusion circle δ is set to 0.005 mm as in the first embodiment. Therefore, the focal depth D is 0.009 mm.

  The maximum fluctuation amount of the focal position in the change of the zoom position in the fourth embodiment is 5D. That is, it is set to 0.045 mm. The maximum fluctuation amount of the focal position in the temperature change is 20D. That is, it is 0.180 mm. As a result, a focus position change of 0.225 mm occurs. Therefore, the imaging position change amount ΔSk due to the movement of the correction lens group may be 0.225 mm. The change amount of the imaging position per 1 mm of the movement amount of the correction lens group is 1.298 mm.

  Therefore, the maximum movement amount Mb for correcting the change in the focus position of the correction lens group is 0.173 mm. The maximum movement amount for zooming of the correction lens group is 8.136 mm. Therefore, the maximum movement amount Mc of the correction lens group is 8.309 mm.

  The moving amount of U2 having the largest moving amount in the variable power lens group is 54.76 mm.

  Table 4 shows values corresponding to the conditional expressions of Example 4. Numerical Example 4 satisfies both of the conditional expressions. A zoom lens capable of satisfactorily correcting the change in the zoom position and the change in the focus position due to the temperature change while realizing high-speed zooming operation and good optical performance. Realized.

  Next, numerical examples 1 to 4 corresponding to the first to fourth embodiments of the present invention will be described. In each numerical example, i indicates the order of the surfaces from the object side, ri is the radius of curvature of the i-th surface from the object side, di is the i-th distance from the i-th surface from the object side, and ndi and νdi are The refractive index and Abbe number of the i-th optical member. The focal length, F number, and angle of view represent values when focusing on an object at infinity. BF is the distance from the final surface of the lens to the image plane.

The aspherical shape is expressed by the following formula, where x is the coordinate in the optical axis direction, y is the coordinate in the direction perpendicular to the optical axis, R is the reference radius of curvature, k is the conic constant, and An is the nth-order aspherical coefficient. It is represented by However, “ex” means “× 10 ^−x ”. A lens surface having an aspherical surface is marked with an asterisk (*) on the right side of the surface number in each table.

x = (y ² / r) / {1+ (1−k · y ² / r ² ) ^0.5 } + A3 · y ³ + A4 · y ⁴ + A5 · y ⁵ + A6 · y ⁶ + A7 · y ⁷ + A8 · y ⁸ + A9 · ^{y 9 + A10 · y 10 +} A11 · y 11 + A12 · y 12 + A13 · y 13 + A14 · y 14 + A15 · y 15 + A16 · y 16

Numerical example 1

Unit mm

Surface data surface number rd nd vd Effective diameter
1 1571.411 5.91 1.90366 31.3 212.83
2 361.491 3.13 205.43
3 389.831 20.85 1.43387 95.1 204.88
4 -1519.134 25.29 203.52
5 379.388 19.40 1.43387 95.1 198.91
6 -1690.060 0.25 198.64
7 270.376 20.46 1.43387 95.1 194.91
8 5840.434 1.18 193.83
9 190.778 14.41 1.59240 68.3 182.16
10 365.545 (variable) 180.35
11 * 11015.733 2.20 2.00330 28.3 48.62
12 41.065 10.49 41.92
13 -62.377 1.40 1.88300 40.8 41.20
14 65.176 9.88 1.95906 17.5 42.38
15 -89.087 2.72 43.74
16 -51.909 1.60 1.83400 37.2 43.88
17 -103.320 (variable) 46.02
18 115.185 11.58 1.59201 67.0 78.48
19 * -2087.691 0.50 78.91
20 142.758 13.08 1.59201 67.0 80.06
21 -231.655 0.20 79.67
22 122.793 2.50 1.80518 25.4 76.01
23 57.717 18.11 1.43387 95.1 71.57
24 -564.234 0.50 70.45
25 * 364.246 6.50 1.49700 81.5 69.33
26 -414.835 (variable) 68.15
27 (Aperture) ∞ 5.89 31.81
28 -147.172 1.40 1.81600 46.6 32.30
29 46.924 1.05 31.20
30 37.303 4.69 1.80809 22.8 31.30
31 420.501 3.37 30.90
32 -76.047 1.40 1.88300 40.8 30.60
33 191.170 11.30 30.40
34 -41.223 1.78 1.65160 58.5 26.67
35 580.472 3.52 1.80518 25.4 27.78
36 -156.414 6.46 28.43
37 -103.332 5.71 1.70154 41.2 30.13
38 -53.979 10.53 31.42
39 -216.194 4.49 1.50137 56.4 32.25
40 -43.973 0.74 32.44
41 -72.585 1.30 1.88300 40.8 31.89
42 61.011 9.51 1.50137 56.4 32.28
43 -35.679 0.20 33.06
44 96.272 8.69 1.49700 81.5 32.15
45 -31.822 1.70 1.88300 40.8 31.45
46 -176.143 2.14 31.79
47 50.459 8.14 1.48749 70.2 31.95
48 -79.751 5.00 31.49
49 ∞ 33.00 1.60859 46.4 60.00
50 ∞ 13.20 1.51633 64.2 60.00
51 ∞ 60.00
Image plane ∞

Aspheric data 11th surface
K = -2.61129e + 006 A 4 = 1.14924e-006 A 6 = -4.20242e-010 A 8 = 7.06050e-012 A10 = 1.71748e-014 A12 = -3.95143e-018 A14 = -2.50492e-020 A16 = 2.74832e-023
A 3 = -7.41007e-007 A 5 = -2.86209e-008 A 7 = 4.68402e-011 A 9 = -6.67517e-013 A11 = -2.87644e-016 A13 = 1.44174e-018 A15 = -1.26241e- 021

19th page
K = -8.09196e + 003 A 4 = 2.70610e-007 A 6 = 1.07566e-009 A 8 = -3.82716e-014 A10 = -1.89869e-016 A12 = 1.74435e-020 A14 = -2.31461e-023 A16 = 5.87253e-027
A 3 = -1.02923e-007 A 5 = -2.58308e-008 A 7 = -1.15844e-011 A 9 = 3.14187e-015 A11 = 2.64931e-018 A13 = 8.56747e-022 A15 = -2.81713e-025

25th page
K = 6.92275e + 001 A 4 = -4.53959e-007 A 6 = -6.59771e-011 A 8 = -3.55842e-013 A10 = -1.48669e-016 A12 = 8.98957e-020 A14 = 6.50522e-022 A16 = 1.24233e-026
A 3 = 7.06566e-007 A 5 = -1.77804e-008 A 7 = 3.13155e-011 A 9 = 8.81552e-016 A11 = -1.46851e-017 A13 = 1.62371e-021 A15 = -1.37737e-023

Various data Zoom ratio 90.00
Wide angle Medium telephoto focal length 8.60 65.53 774.03
F number 1.80 1.79 4.00
Angle of view 32.60 4.80 0.41
Image height 5.50 5.50 5.50
Total lens length 641.10 641.10 641.10
BF 18.00 18.00 18.00

d10 3.03 140.03 186.75
d17 279.71 118.33 3.07
d26 3.00 27.38 95.93

Entrance pupil position 126.14 812.29 9423.65
Exit pupil position 141.46 141.46 141.46
Front principal point position 135.34 912.61 15050.41
Rear principal point position 9.40 -47.53 -756.02

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 248.14 110.88 64.60 -17.20
2 11 -27.25 28.28 3.76 -16.43
3 18 70.50 52.98 12.00 -25.30
4 27 40.01 145.21 58.78 16.17

Numerical example 2

Unit mm

Surface data surface number rd nd vd Effective diameter
1 8000.000 6.00 1.83400 37.2 203.23
2 373.691 1.54 196.39
3 361.776 26.52 1.43387 95.1 195.96
4 -518.880 25.95 194.72
5 370.520 17.79 1.43387 95.1 195.79
6 -3369.467 0.25 195.31
7 241.028 17.39 1.43387 95.1 190.20
8 861.689 1.20 188.93
9 203.790 14.06 1.49700 81.5 180.22
10 421.379 (variable) 178.48
11 * 3657.872 2.20 2.00330 28.3 43.69
12 40.621 10.00 38.07
13 -45.369 1.40 1.88300 40.8 37.29
14 98.142 5.97 1.95906 17.5 38.23
15 -67.097 0.69 38.36
16 -64.854 1.60 1.75500 52.3 38.12
17 -212.532 (variable) 38.80
18 140.986 10.25 1.56907 71.3 73.92
19 * -186.006 0.50 74.42
20 102.215 13.53 1.56907 71.3 76.51
21 -162.778 0.20 76.24
22 159.988 2.50 1.84666 23.8 71.21
23 60.722 13.35 1.43875 94.9 66.79
24 -6797.000 (variable) 65.77
25 * 254.766 5.14 1.60311 60.6 64.42
26 -369.734 (variable) 63.74
27 (Aperture) ∞ 2.93 33.76
28 -155.154 1.40 1.83481 42.7 32.24
29 24.535 6.89 1.76182 26.5 30.20
30 2780.241 3.70 29.80
31 -96.909 1.85 1.83481 42.7 28.78
32 71.731 0.15 28.46
33 33.014 4.69 1.84666 23.8 28.89
34 155.745 5.42 28.23
35 -122.347 1.58 1.83481 42.7 26.36
36 58.258 7.24 25.83
37 -72.547 1.91 1.71736 29.5 26.38
38 34.123 15.00 1.65160 58.5 27.73
39 -50.824 3.00 30.40
40 -403.126 4.32 1.54814 45.8 30.64
41 -47.125 3.12 30.76
42 -68.761 3.07 1.88300 40.8 29.52
43 37.681 9.19 1.51742 52.4 29.92
44 -49.851 0.20 30.96
45 164.690 7.05 1.49700 81.5 31.29
46 -34.793 2.50 1.83481 42.7 31.30
47 -98.072 1.18 32.20
48 68.401 7.25 1.54814 45.8 32.48
49 -56.118 14.45 32.28
50 ∞ 33.00 1.60859 46.4 60.00
51 ∞ 13.20 1.51633 64.2 60.00
52 ∞ 60.00
Image plane ∞

Aspheric data 11th surface
K = -9.90196e + 004 A 4 = 1.00187e-006 A 6 = -7.44468e-010 A 8 = 5.01326e-013

19th page
K = -1.87503e + 001 A 4 = 2.45550e-007 A 6 = 7.82502e-011 A 8 = -3.75504e-015

25th page
K = 1.36886e + 001 A 4 = -1.59307e-007 A 6 = -1.02866e-010 A 8 = 3.28743e-015

Various data Zoom ratio 99.96
Wide angle Medium Telephoto focal length 8.90 84.98 889.65
F number 1.80 1.80 4.60
Angle of View 31.72 3.70 0.35
Image height 5.50 5.50 5.50
Total lens length 615.79 615.79 615.79
BF 10.17 10.17 10.17

d10 2.71 151.20 198.10
d17 269.28 96.90 1.99
d24 0.45 5.41 27.78
d26 0.86 19.79 45.44

Entrance pupil position 124.84 917.43 9513.22
Exit pupil position 149.25 149.25 149.25
Front principal point position 134.31 1054.33 16093.81
Rear principal point position 1.27 -74.81 -879.48

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 259.25 110.70 62.07 -20.39
2 11 -25.74 21.85 3.58 -12.51
3 18 69.30 40.33 5.79 -20.84
4 25 249.89 5.14 1.31 -1.90
5 27 39.72 154.30 57.33 19.89

Numerical Example 3

Unit mm

Surface data surface number rd nd vd Effective diameter
1 7000.000 6.00 1.83400 37.2 195.69
2 345.379 2.00 189.57
3 345.379 25.91 1.43387 95.1 190.61
4 -527.375 20.74 191.16
5 331.921 18.73 1.43387 95.1 193.34
6 -4082.422 0.25 192.86
7 264.903 19.29 1.43387 95.1 188.46
8 3887.712 0.25 187.25
9 171.964 16.12 1.43875 94.9 174.67
10 367.798 (variable) 172.80
11 1547.347 2.00 2.00330 28.3 42.77
12 43.466 8.24 37.79
13 -55.129 2.00 1.88300 40.8 37.77
14 63.246 9.63 1.92286 18.9 41.36
15 -66.171 1.02 42.37
16 -59.413 2.00 1.77250 49.6 42.43
17 * 2736.384 (variable) 44.72
18 108.766 12.13 1.56907 71.3 81.41
19 * -3543.181 0.20 81.81
20 100.674 13.34 1.49700 81.5 83.34
21 -613.181 0.20 82.78
22 103.700 2.50 1.84666 23.8 79.37
23 60.132 20.33 1.43875 94.9 74.98
24 -268.844 0.20 73.52
25 * 201.189 5.73 1.43875 94.9 71.02
26 -889.802 (variable) 69.63
27 (Aperture) ∞ 5.19 32.62
28 186.208 1.40 1.81600 46.6 29.05
29 25.515 5.51 1.84666 23.8 27.14
30 65.304 4.72 25.92
31 -74.674 1.40 1.88300 40.8 24.90
32 -336.961 3.50 24.76
33 65.994 2.75 1.48749 70.2 23.90
34 -449.738 0.40 23.53
35 17.296 5.07 1.64000 60.1 21.81
36 197.534 0.90 1.84666 23.8 20.59
37 18.033 5.51 18.30
38 182.659 0.80 1.78800 47.4 17.05
39 11.672 3.59 1.80809 22.8 16.07
40 35.812 1.13 15.72
41 97.623 1.00 1.88300 40.8 15.64
42 43.673 5.00 15.44
43 968.789 6.61 1.48749 70.2 33.07
44 -42.681 0.20 33.28
45 -147.760 1.60 1.88300 40.8 32.40
46 38.666 10.22 1.49700 81.5 32.01
47 -52.689 1.50 32.65
48 168.155 8.81 1.56732 42.8 32.33
49 -28.418 1.60 1.88300 40.8 31.93
50 -157.717 0.20 32.63
51 106.332 7.51 1.48749 70.2 32.74
52 -42.361 14.00 32.52
53 ∞ 33.00 1.60859 46.4 60.00
54 ∞ 13.20 1.51633 64.2 60.00
55 ∞ 60.00
Image plane ∞

Aspheric data 17th surface
K = -2.53234e + 004 A 4 = -4.13015e-007 A 6 = -2.14627e-010 A 8 = 2.26588e-013

19th page
K = 5.22565e + 003 A 4 = 8.81676e-008 A 6 = 1.58180e-012 A 8 = 6.14872e-015

25th page
K = -9.48244e + 000 A 4 = -7.57187e-007 A 6 = -1.54476e-010 A 8 = 2.42122e-014

Various data Zoom ratio 100.00
Wide angle Medium Telephoto focal length 18.67 189.61 1867.15
F number 3.71 3.71 9.84
Angle of View 16.41 1.66 0.17
Image height 5.50 5.50 5.50
Total lens length 619.23 619.23 619.23
BF 11.94 11.94 11.94

d10 3.07 141.07 176.64
d17 266.10 100.56 1.96
d26 3.00 30.54 93.57
d55 11.94 11.94 11.94

Entrance pupil position 124.58 996.17 11114.47
Exit pupil position -252.97 -252.97 -252.97
Front principal point position 141.93 1050.07 -178.60
Rear principal point position -6.73 -177.67 -1855.21

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 238.05 109.29 59.18 -20.74
2 11 -25.00 24.89 4.19 -12.46
3 18 66.50 54.63 13.57 -26.05
4 27 -6566.83 146.31 -3550.86 -7984.43

Numerical Example 4

Unit mm

Surface data surface number rd nd vd Effective diameter
1 -210.024 2.30 1.72047 34.7 82.63
2 145.102 4.91 77.63
3 491.656 2.20 1.84666 23.8 77.24
4 236.100 8.88 1.43875 94.9 76.67
5 -196.805 0.40 76.63
6 152.079 11.02 1.43387 95.1 75.76
7 -147.909 6.94 75.65
8 136.777 7.72 1.59240 68.3 73.35
9 -441.404 0.15 73.09
10 62.631 6.49 1.72916 54.7 67.82
11 131.204 (variable) 67.13
12 72.053 1.00 1.88300 40.8 26.69
13 14.820 6.20 21.30
14 -45.643 6.88 1.80809 22.8 20.98
15 -12.496 0.75 1.88300 40.8 20.60
16 94.745 0.18 20.49
17 30.451 2.41 1.66680 33.0 20.72
18 82.062 (variable) 20.48
19 -38.647 0.75 1.75700 47.8 21.65
20 60.193 2.42 1.84649 23.9 22.99
21 -1560.081 (variable) 23.43
22 -172.490 3.22 1.64000 60.1 27.72
23 -44.456 0.15 28.38
24 84.388 3.66 1.51633 64.1 29.60
25 -130.776 (variable) 29.73
26 (Aperture) ∞ 2.00 29.78
27 63.114 6.26 1.51742 52.4 29.82
28 -38.329 1.00 1.83400 37.2 29.58
29 -187.721 36.00 29.64
30 -56.536 2.41 1.51633 64.1 26.08
31 -35.722 0.10 26.22
32 -503.242 0.80 1.80 100 35.0 25.72
33 30.789 5.54 1.50127 56.5 25.72
34 -125.107 0.15 26.12
35 61.177 5.93 1.48749 70.2 26.53
36 -36.075 0.85 1.88300 40.8 26.48
37 -84.336 0.23 26.82
38 53.704 3.66 1.51633 64.1 26.78
39 -144.281 4.50 26.54
40 ∞ 33.00 1.60859 46.4 40.00
41 ∞ 13.20 1.51633 64.1 40.00
42 ∞ 40.00
Image plane ∞

Various data Zoom ratio 21.88
Wide angle Medium Telephoto focal length 7.80 20.67 170.68
F number 1.80 1.80 2.63
Angle of view 35.19 14.90 1.85
Image height 5.50 5.50 5.50
Total lens length 272.06 272.06 272.06
BF 7.01 7.01 7.01

d11 0.41 27.98 55.17
d18 61.23 18.97 11.88
d21 6.98 15.28 1.94
d25 2.17 8.56 1.79

Entrance pupil position 48.98 120.60 765.75
Exit pupil position 1826.32 1826.32 1826.32
Front principal point position 56.82 141.51 952.44
Rear principal point position -0.79 -13.66 -163.67

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear principal point position
1 1 71.50 51.01 33.46 1.92
2 12 -13.80 17.42 2.44 -9.45
3 19 -57.00 3.17 -0.09 -1.82
4 22 48.00 7.03 2.82 -1.69
5 26 52.87 115.63 54.40 -48.14

Table 1 shows the correspondence between each embodiment and each conditional expression described above.

U1 1st group U2 2nd group U3 3rd group U4 4th group U5 5th group U6 6th group U7 7th group U11 11th group U12 12th group U13 13th group SP Aperture stop 1 Focus lens group 2 Variable magnification Lens group 3 Aperture stop 4 Front relay lens group 6 Rear relay lens group

Claims (11)

A focusing lens group which moves for focusing, two or more variable power lens unit which moves for the arranged on the image side of the focusing lens group and zooming, a stop, a relay lens group does not move for zooming A zoom lens having
The two or more lens group or the relay lens group is moved in order to correct for variations in focus position due to one or more factors including the attachment and detachment of the extender group as a sub-lens group in the relay lens group Including a correction group as a lens group or sub-lens group ,
Drive means for driving the correction group; and control means for controlling the drive means so as to correct a variation in focus position caused by the one or more factors.
The maximum moving amount of the correcting unit and Mc, and Mb maximum moving amount of the correction group for correcting the variation of the focus position, the maximum of the imaging position when the correction unit is moved by the maximum moving amount Mb The amount of change is ΔSk, and the maximum amount of movement of the variable power lens group included in the two or more variable power lens groups is Mm.
0.001 <Mc / Mm <0.300
0.3 <| ΔSk | / Mb <3.0
A zoom lens characterized by satisfying the following formula:   Focus lens group that moves for focusing, two or more variable magnification lens groups that are arranged on the image side of the focus lens group and move for zooming, a stop, and a relay lens group that does not move for zooming A zoom lens having
  The two or more zoom lens groups include a correction group as a zoom lens group that moves in order to correct a variation in focus position caused by one or more factors,
  The maximum movement amount of the correction group is Mc, the maximum movement amount of the correction group for correcting the variation of the focus position is Mb, and the maximum imaging position when the correction group is moved by the maximum movement amount Mb. The amount of change is ΔSk, and the maximum movement amount of the variable power lens group included in the two or more variable power lens groups is Mm
    0.001 <Mc / Mm <0.300
    0.3 <| ΔSk | / Mb <3.0
A zoom lens characterized by satisfying the following formula: The open F number of the zoom lens is Fno, the allowable circle of confusion is δ, and the depth of focus is D.
D = Fno × δ
0.3 <Mb / D <300.0
The zoom lens according to claim 1 or claim 2, characterized by satisfying the composed expression. Driving means for driving the correction group ;
Control means for controlling the drive means so as to correct a variation in focus position caused by the one or more factors;
The zoom lens according to claim 2 , further comprising: Storage means for storing correction information for correcting a variation in focus position caused by the one or more factors;
Said control means, said one and more factors, and based on the correction information stored in said storage means, for controlling said drive means,
The zoom lens according to claim 1 , wherein the zoom lens is a zoom lens. Detecting means for detecting the one or more factors;
Said control means, said one and more factors detected by the detecting means, and based on the correction information stored in said storage means, for controlling said drive means,
The zoom lens according to claim 5 . The zoom lens according to claim 4 , wherein the one or more factors include attachment / detachment of an extender group as a sub lens group in the relay lens group. The zoom lens according to claim 1 , wherein the correction group is included in the relay lens group. The zoom lens according to claim 1 , wherein the correction group is included in the two or more variable magnification lens groups. The zoom lens according to any one of claims 1 to 9 , wherein the correction group includes one or more lenses and three or less lenses. The zoom lens according to any one of claims 1 to 10 ,
An imaging device for receiving light from said zoom lens,
An imaging device comprising:

Images