JP2019078831A - Zoom lens and imaging apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a zoom lens which is advantageous in terms of both small size and light weight and optical performance. SOLUTION: The zoom lens is a positive first group fixed during scaling in order from the object side, a negative second group moving for scaling, and at least one scaling lens group moving for scaling. The first group consists of a positive lens group fixed during scaling, and the first group is a first sub-lens group that does not move in order from the object side to the image side for focusing, and the focal length of the object is changed from infinity. It consists of a positive second sub-lens group that moves to the object side and a positive third sub-lens group that moves to the object side to change the focal length from infinity, and consists of a short-range object from an infinity object. The second sub-lens group and the third sub-lens group move in different trajectories when focusing on, and the first group has an aspherical surface, and the amount of aspherical surface in the maximum effective diameter of the light beam is the amount of the first group. It is characterized by setting the focal length appropriately. [Selection diagram] Fig. 1

Description

  The present invention relates to a zoom lens and an imaging device.

  In recent years, a zoom lens having a large aperture, a high zoom ratio, a reduction in size, and a high optical performance is required for an imaging apparatus such as a television camera for broadcast, a silver halide film camera, a digital still camera, and a video camera. . As a general-purpose zoom lens with a large aperture ratio and a high zoom ratio, a positive lead type four-unit zoom lens consisting of four lens units as a whole and having a lens unit of positive refractive power on the object side is known. There is. This four-unit zoom lens includes, in order from the object side to the image side, a first lens group for focusing, a second lens group for negative power for magnification change, and a lens for correcting image plane variation associated with magnification change. It comprises a third lens unit and a fourth lens unit of positive refractive power for imaging.

  In Patent Document 1, an eleventh lens group G11 of negative refractive power, a twelfth lens group G12 of positive refractive power, and a thirteenth lens group G13 of positive refractive power are arranged in order from the object side to the image side in the first lens group. It is divided into In addition, an inner focus zoom lens is proposed which performs focusing by moving the twelfth lens group G12 on the optical axis.

Patent No. 446925 gazette

  Along with the increase in the number of pixels of an imaging device, high optical performance is required in all zoom areas and all focus areas. In the positive lead zoom lens described above, in order to achieve both size reduction and high optical performance, it is necessary to appropriately set the refractive power and configuration of each lens, in particular, the power arrangement and lens configuration in the first lens group. is there.

  In Patent Document 1, although the high performance is achieved by increasing the number of lenses in the first lens group to increase the degree of freedom in aberration correction, the increase in the number of lenses of the first lens group having a large effective lens diameter is Cause an increase in the total weight of the lens system.

  An exemplary object of the present invention is to provide a zoom lens that is advantageous in terms of both the small size and light weight and the optical performance.

In order to achieve the above object, in the zoom lens according to the present invention, in order from the object side to the image side, a first lens unit having a positive refractive power that does not move for zooming, a negative lens that moves for zooming A second lens group having a refracting power of at least one variable magnification lens group which moves for zooming, and a lens group having a positive refractive power which does not move for zooming, the first lens group A first sub lens unit which does not move for focusing from the object side to the image side, and a second sub lens having a positive refractive power which moves to the object side to change the focusing object distance from infinity. And a third sub-lens group having a positive refractive power that moves toward the object side to change the focusing object distance from infinity, and the second sub lens unit changes the focusing object distance from infinity to The lens group and the third sub lens group are mutually Moving at different loci on the first lens group includes at least one aspherical surface, wherein at the maximum effective ray diameter aspherical amount of the aspherical Delta] h, the focal length of the first lens group as f1,
5 × 10 ⁻⁵ <| Δh / f 1 | <5 × 10 ⁻³
It is characterized by satisfying the following conditional expression.

  According to the present invention, it is possible to provide, for example, a zoom lens that is advantageous in terms of both small size and light weight and optical performance.

12A is a lens sectional view of the zoom lens according to Numerical Example 1 when focusing on an object at infinity at the (A) wide angle end, and (B) when focusing on 1.5 m (from the first surface) at the wide angle end It is lens sectional drawing of. In the numerical example 1, (A) wide-angle end at infinity focusing, (B) object distance 1.5 m (from the first surface) wide-angle end at focusing, (C) telephoto end at infinity It is a longitudinal aberration figure of the telephoto end at the time of an end, and (D) object distance 1.5 m (from the 1st surface) focusing. 12A is a lens sectional view of the zoom lens according to Numerical Example 2 when focusing on an object at infinity at the (A) wide angle end, and (B) when focusing on 1.5 m (from the first surface) at the wide angle end It is lens sectional drawing of. In the second embodiment, (A) wide-angle end at infinity focusing, (B) wide-angle end at object distance 1.5 m (from the first surface) focusing, (C) telephoto end at infinity It is a longitudinal aberration figure of the telephoto end at the time of an end, and (D) object distance 1.5 m (from the 1st surface) focusing. 6A is a sectional view of a zoom lens according to Numerical Example 3 when focusing on an object at infinity at the (A) wide angle end, and (B) when focusing on 1.5 m (from the first surface) at the wide angle end It is lens sectional drawing of. In the numerical example 3, (A) wide-angle end at infinity focusing, (B) object distance 1.5 m (from the first surface) wide-angle end at focusing, (C) telephoto end at infinity It is a longitudinal aberration figure of the telephoto end at the time of an end, and (D) object distance 1.5 m (from the 1st surface) focusing. 12A is a lens sectional view of the zoom lens according to Numerical Example 4 when focusing on an object at infinity at the (A) wide angle end, and (B) when focusing on 1.5 m (from the first surface) at the wide angle end It is lens sectional drawing of. In the fourth embodiment, (A) wide-angle end at infinity focusing, (B) wide-angle end at object distance 1.5 m (from the first surface) focusing, and (C) telephoto end at infinity It is a longitudinal aberration figure of the telephoto end at the time of an end, and (D) object distance 1.5 m (from the 1st surface) focusing. 12A is a lens sectional view of the zoom lens according to Numerical Example 5 when focusing on an infinite distance object at the (A) wide angle end of the zoom lens and (B) when focusing on 1.5 m (from the first surface) at the wide angle end It is lens sectional drawing of. In the fifth embodiment, (A) wide-angle end at infinity focusing, (B) wide-angle end at object distance 1.5 m (from the first surface) focusing, and (C) telephoto end at infinity It is a longitudinal aberration figure of the telephoto end at the time of an end, and (D) object distance 1.5 m (from the 1st surface) focusing. FIG. 1 is a schematic view of a main part of an imaging device (television camera system) using a zoom lens of each embodiment as a photographing optical system. It is a paraxial layout showing an on-axis paraxial ray entering the lens group before and after focusing.

Hereinafter, embodiments of the present invention will be described in detail based on the attached drawings.
The zoom lens according to the present invention includes, in order from the object side, a first lens group having a positive refractive power which is fixed during zooming, a second lens group having a negative refractive power which moves for zooming, and at least one zooming lens. In the zoom lens constituted by the lens unit and the lens unit having a positive refractive power that does not move for zooming, the first lens unit does not move for focusing in order from the object side to the image side. Lens group, move to the object side to change the focusing object distance from infinity, move to the object side to change the focusing object distance from infinity to the second sub lens group having positive refractive power , The third sub-lens group having positive refractive power,
A zoom lens having at least one aspheric surface, wherein the second sub lens unit and the third sub lens unit move on different trajectories in order to change the object distance to be focused from infinity. It is characterized by being.

In the present invention, an optical operation in the case of adopting the above-described focusing method will be described.
First, the problem of the focusing method using floating performed by moving a plurality of moving groups by different amounts at the time of focusing from an infinite distance object to a close distance object, which is the prior art, will be described with reference to FIG.

  The first lens group L1 includes a first sub lens group LA fixed at the time of focusing from the object side, a second sub lens group LB1 moving at the time of focusing, and a third sub lens group LB2 moving at the time of focusing doing. The paraxial ray at the time of an infinite distance object is shown by a solid line, and the position on the optical axis of the second sub lens unit LB1 and the third sub lens unit LB2 at this time is b1 and b2, the distance is t, and each paraxial ray The heights are shown as Ha, Hb1 and Hb2. On the other hand, a paraxial ray for a certain finite distance object is indicated by a dotted line, and the positions of the second sub lens unit LB1 and the third sub lens unit LB2 on the optical axis at this time are b1 'and B2' Each paraxial ray height is shown as Ha ', Hb1', Hb2 'for t <T). The paraxial axial ray is a paraxial ray when the focal length of the entire optical system is normalized to 1 and light of height 1 from the optical axis is incident parallel to the optical axis of the optical system. It is. The inclination of a ray is the difference in height of the ray in a given section divided by the length of the section. In the following, it is assumed that the object is on the left side of the optical system, and light rays entering the optical system from the object side are treated as traveling from left to right. The incident angle to the optical system is positive clockwise as measured from the optical axis and negative counterclockwise.

  The position on the optical axis when the space t between the second sub lens unit LB1 and the third sub lens unit LB2 arranged in the same positional relationship as at the infinite distance object is the second sub lens in the same finite distance object The position b1 ′ ′ of the group LB1 is closer to the image plane than the position b1 ′, and the position b2 ′ ′ of the third sub lens group LB2 is closer to the object than the position b2 ′. Further, the heights of paraxial ray at each position are taken as Ha ′ ′, Hb1 ′ ′, Hb2 ′ ′.

Next, focusing on changes in paraxial ray heights of the LB1 and LB2 groups for t <T and t = T,
Hb1 '> Hb1 ′ ′
Hb 2 ′ <Hb 2 ′ ′
It is.

Here, in the third-order aberration theory, the third-order aberration coefficient I of the spherical aberration is proportional to the fourth power of the paraxial ray height h, and the third-order aberration coefficient III of the astigmatism is proportional to the square of the paraxial ray height h . Therefore, the second sub-lens group LB1 and the third sub-lens group LB2 have the following effects of change of the third-order aberration coefficient of spherical aberration and axial chromatic aberration when t <T than when t = T. .
[1] Second sub-lens group LB1: The third-order aberration coefficient I of the spherical aberration changes in the positive direction, and the third-order aberration coefficient III of the astigmatism also changes in the positive direction. It changes to under.
[2] Third sub-lens group LB2: The third-order aberration coefficient I of the spherical aberration changes in the negative direction, and the third-order aberration coefficient III of the astigmatism also changes in the negative direction. Therefore, the spherical aberration goes to over, the astigmatism also Change to over.

  The focusing method using floating skillfully utilizes the aberration fluctuation due to the movement of the second sub lens unit LB1 and the third sub lens unit LB2, and suppresses the aberration fluctuation due to focusing.

  In the focusing method using floating, in general, the difference between Hb1-Ha at the time of an infinite distance object and Hb1'-Ha 'at the time of a finite distance object is reduced, thereby reducing variation of spherical aberration and astigmatism. It is possible to Further, by moving the third sub lens unit to the image plane side, spherical aberration and astigmatism are overcorrected at the closest object in-focus point.

  On the other hand, even in a focusing method using floating, further miniaturization and further enhancement of optical performance are desired. Therefore, in order to push out the principal point of the first lens group to the image side, it is necessary to increase the power of the first sub lens group LA, and to reduce the extension amount of the focus group of the second sub lens group LB1. The power of the two sub lens unit LB1 needs to be increased. As a result, Hb1'-Ha 'at the finite distance object becomes larger than Hb1-Ha at the infinite distance object, and fluctuations of spherical aberration and astigmatism increase to under, and various aberrations at the time of focusing There is a problem that the fluctuation of

  Also, if the powers of the first sub lens group LA and the second sub lens group LB1 become too strong, the third sub lens group LB2 can not correct the spherical aberration and the astigmatism at the time of close object focusing. It will

In the present invention, an aspheric lens is provided in any one of the first sub lens group, the second sub lens group, and the third sub lens group in order to solve the above problems. The aspheric surface of the aspheric lens has a spherical surface having a paraxial radius of curvature as a reference surface, and a distance from the reference surface to the aspheric surface extending in parallel to the optical axis as an aspheric surface at the maximum light ray effective diameter When the aspheric amount is Δh and the focal length of the first lens unit is f1, the following condition is satisfied.
5 × 10 ⁻⁵ <| Δh / f 1 | <5 × 10 ⁻³ (1)

As a result, even in a focusing method using floating, the first lens group is configured with a relatively small number of components, and both small size, light weight and high optical performance are achieved.
If the lower limit value of the conditional expression (1) is exceeded, the aspheric amount becomes too small with respect to the refractive power of the first lens group, and fluctuations in spherical aberration and astigmatism accompanying zooming and focusing can not be suppressed. If the upper limit is exceeded, the aspheric amount becomes too large with respect to the refractive power of the first lens group, which is not preferable because fluctuations in spherical aberration and astigmatism associated with zooming and focusing become excessive.
More preferably, conditional expression (1) may be set as follows.
1 × 10 ⁻⁴ <| Δh / f 1 | <4.7 × 10 ⁻³ (1a)

More preferably, the focal length of the first lens group is f1, the focal length of the first sub lens group is f11, the focal length of the second sub lens group is f12, and the focal length of the third sub lens group is f13, the first lens Assuming that the average refractive index of d-line of the glass material constituting the group is N1, the average Abbe number of the glass material constituting the first lens group is dd1, and the average partial dispersion ratio of the glass material constituting the first lens group is θ1. The following conditional expressions should be satisfied.
−20 <f11 / f1 <−4.0 (2)
1.1 <f12 / f1 <2.4 (3)
1.9 <f13 / f1 <4.0 (4)
1.42 <N1 <1.70 (5)
55 <νd1 <90 (6)
0.52 <θ1 <0.58 (7)
The Abbe number お よ び and the partial dispersion ratio θ are the g-line (wavelength 435.8 nm) of the Fraunhofer line, the f-line (wavelength 486.1 nm), the d-line (wavelength 587.6 nm), and the c-line (wavelength 656). The refractive index for .3 nm is Ng, NF, Nd, and NC respectively, and .nu. = (Nd-1) / (NF-NC).
θ = (Ng-NF) / (NF-NC)
Is represented by

  Conditional expression (2) defines the ratio of the focal lengths of the first lens group and the first sub lens group. The negative power of the first sub lens unit becomes relatively weak, and if it falls below the lower limit value of the conditional expression (1), it becomes difficult to push the image side principal point of the first lens unit to the image side. As a result, the diameter of the front lens increases, which is disadvantageous for downsizing. The negative power of the first sub lens unit becomes relatively strong, and when the value exceeds the upper limit value, it becomes difficult to satisfactorily correct various aberrations.

  Conditional expression (3) defines the ratio of the focal lengths of the first lens group and the second sub lens group. When the positive power of the second sub lens unit becomes relatively strong and falls below the lower limit value, it becomes difficult to suppress aberration fluctuation during focusing. The positive power of the second sub lens unit becomes relatively weak, and when it exceeds the upper limit value, the amount of movement at the time of focusing increases, which is disadvantageous for downsizing.

  Conditional expression (4) defines the ratio of the focal length of the first lens group to the focal length of the third sub lens group. When the positive power of the third sub lens unit becomes relatively strong and falls below the lower limit value, it becomes difficult to suppress aberration fluctuation during focusing. The positive power of the third sub lens unit becomes relatively weak, and when it exceeds the upper limit value, the amount of movement at the time of focusing increases, which is disadvantageous for miniaturization.

Conditional expressions (5) to (7) define the glass material constituting the first lens group.
If the lower limit value of the conditional expression (5) is not reached, the curvature radius of the lens constituting the first lens group becomes small, and it becomes difficult to suppress the aberration fluctuation accompanying zooming and the aberration fluctuation accompanying focusing. If the upper limit value is exceeded, it will be difficult to satisfy the conditional expression (6).

  If the lower limit value of conditional expression (6) is exceeded, correction of axial chromatic aberration at the telephoto end in particular will be insufficient. If the upper limit value is exceeded, axial chromatic aberration at the telephoto end is overcorrected.

  Below the lower limit value of the conditional expression (7), secondary spectral correction of axial chromatic aberration at the telephoto end in particular becomes excessive, and when the upper limit value is exceeded, the correction becomes insufficient, which is not good.

By simultaneously satisfying the conditional expressions (2) to (7), a small size and high optical performance are achieved. More preferably, conditional expressions (2) to (7) may be set as follows.
−18.5 <f11 / f1 <−6.0 (2a)
1.4 <f12 / f1 <2.0 (3a)
2.5 <f13 / f1 <3.5 (4a)
1.47 <N1 <1.62 (5a)
65 <νd1 <80 (6a)
0.53 <θ1 <0.57 (7a)

More preferably, the maximum value of the combined focal length of the second sub lens group and the third sub lens group is (f12 + f13) max, the minimum value is (f12 + f13) min, and the second sub lens group and the third sub lens group are configured. Assuming that the average refractive index of the d-line of the glass material is N2, the average Abbe number is dd2, and the average partial dispersion ratio is θ2, it is preferable to satisfy the following conditional expression.
1.0 <f13 / f12 <2.5 (8)
1.0 <(f12 + f13) max / (f12 + f13) min <1.1
... (9)
1.42 <N2 <1.7 (10)
63 <d d 2 <95 (11)
0.51 <θ2 <0.56 (12)

  Conditional expression (8) defines the ratio of the focal length of the second sub lens group to the focal length of the third sub lens group. The power of the third sub lens group becomes relatively weak with respect to the second sub lens group, and if the power is below the lower limit value, the extension amount of the second sub lens group becomes small, which is advantageous for downsizing, but at focusing Aberration fluctuation suppression becomes difficult. When the power of the third sub lens unit becomes relatively strong with respect to the second sub lens unit, the extension amount of the second sub lens unit increases, which is disadvantageous for downsizing.

  Conditional expression (9) defines the ratio of the longest focal length to the shortest focal length of the combined focal length of the second and third sub lens groups which changes during focusing. When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move on different trajectories. To approach the lower limit value means that the loci of the second sub lens group and the third sub lens group approach the same locus. As a result, it is not good because it becomes difficult to suppress aberration fluctuation associated with focusing. In addition, the second sub lens group and the third sub lens group move on different trajectories, and the distance between the second sub lens group and the third sub lens group increases. If the upper limit is exceeded, miniaturization becomes difficult.

  Conditional expressions (10) to (12) define glass materials constituting the second sub lens group and the third sub lens group. If the lower limit value of the conditional expression (10) is not reached, the radius of curvature of the lenses constituting the second sub lens group and the third sub lens group becomes small, and it becomes difficult to suppress aberration fluctuation accompanying zooming and aberration fluctuation accompanying focusing. . If the upper limit value is exceeded, it will be difficult to satisfy the conditional expression (11).

  If the lower limit value of conditional expression (11) is exceeded, correction of axial chromatic aberration at the telephoto end in particular will be insufficient. If the upper limit value is exceeded, axial chromatic aberration at the telephoto end is overcorrected.

  If the lower limit value of the conditional expression (12) is not reached, secondary spectrum correction of axial chromatic aberration at the telephoto end will be excessive. If the upper limit value is exceeded, the correction will be insufficient.

By simultaneously satisfying the conditional expressions (8) to (12), a small size and high optical performance are achieved. More preferably, conditional expressions (8) to (12) may be set as follows.
1.3 <f13 / f12 <2.1 (8a)
1.005 <(f12 + f13) max / (f12 + f13) min <1.018
... (9a)
1.45 <N2 <1.60 ・ ・ ・ (10a)
68 <νd2 <90 (11a)
0.52 <θ2 <0.55 (12a)

  More preferably, the second sub lens group is composed of two convex lenses, and the third sub lens group is composed of one positive meniscus lens having a convex surface facing the object side. With the above configuration, small size and high optical performance are achieved.

  FIG. 1 is a lens cross-sectional view when focusing on an infinite distance object and an object distance of 1.5 m at the wide angle end (short focal length end) according to Numerical Embodiment 1 as Embodiment 1 of the present invention. Fig. 2 shows (A) wide-angle end · infinity focus, (B) wide-angle end · 1.5 m (from the first surface) focus, (C) telephoto end · infinity focus, (D) telephoto end It is an aberrational figure at the time of 1.5 m (from the 1st surface) focus. In each lens sectional view, the left side is the object (object) side (front), and the right side is the image side (rear). U1 is a first lens group of positive refractive power that is always fixed. U2 is a second lens unit for zooming, and zooming from the wide-angle end to the telephoto end is performed by moving the optical axis on the image plane side. U3 and U4 are both a third lens group and a fourth lens group for zooming, and move on the optical axis from the wide-angle end to the telephoto end. SP is a fixed aperture stop at all times, and U5 is a fifth lens group (relay group) having an imaging action. In the fifth lens unit U5, a converter (extender) for focal length conversion may be mounted. In addition, the lens units after the fifth lens unit may be moved for zooming, vibration reduction, or the like, and may be composed of a plurality of units. DG is a color separation prism, an optical filter, etc., and is shown as a glass block in the figure. IP is an image plane and corresponds to an imaging surface of a solid-state imaging device.

  In each aberration diagram, straight lines and broken lines in spherical aberration are e-line and g-line, respectively. The solid line and the broken line in astigmatism are a sagittal image plane (ΔS) and a meridional image plane (ΔM), respectively, and lateral chromatic aberration is represented by g-line. The astigmatism and the magnification chromatic aberration indicate the amount of aberration when the ray passing through the center of the light beam at the stop position is a chief ray. ω is a half angle of view on the paraxial axis, and Fno is an F number. In each of the following embodiments, the wide-angle end and the telephoto end refer to zooming positions when the zooming lens unit is positioned at both ends of the movable range on the optical axis.

  The present invention reduces the fluctuation of various aberrations associated with zooming and focusing by appropriately setting the power arrangement and lens configuration of the first lens group, and obtains a zoom lens achieving miniaturization and an image pickup apparatus having the same. I can do it.

In Numerical Embodiment 1, the first lens unit U1, the first sub lens unit U11, the second sub lens unit U12, and the third sub lens unit U13 will be described.
The first lens unit U1 corresponds to the first lens surface to the fourteenth lens surface in the numerical value example 1.

  The first sub lens unit U11 corresponds to the first lens surface to the eighth lens surface in the numerical value example 1, and is composed of, in order from the object side, a negative lens, a positive lens, a negative lens, and a positive lens. The first sub lens unit U11 is fixed at the time of focusing.

  The second sub lens unit U12 corresponds to the ninth lens surface to the twelfth lens surface in the numerical value example 1, and is configured by two positive lenses. The second sub lens unit U12 moves toward the object side at the time of focusing on a short distance object.

  The third sub lens unit U13 corresponds to the thirteenth lens surface to the fourteenth lens surface in the numerical value example 1, and includes one positive meniscus lens. Furthermore, the thirteenth lens surface has an aspheric surface. The third sub lens unit U13 is moved to the object side at the time of short distance focusing.

  When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move along different trajectories. Table 1 shows values corresponding to the respective conditional expressions in the present embodiment. The present numerical example satisfies the conditional expressions of the expressions (1) to (12), and achieves good optical performance.

In Embodiment 2 as Numerical Embodiment 2, the first lens unit U1, the first sub lens unit U11, the second sub lens unit U12, and the third sub lens unit U13 will be described.
The first lens unit U1 corresponds to the first lens surface to the tenth lens surface in the numerical value example 2.

  The first sub lens unit U11 corresponds to the first lens surface to the fourth lens surface in the numerical value example 2, and is composed of a negative lens and a positive lens in order from the object side. Furthermore, the first lens surface has an aspheric surface. The first sub lens unit is fixed at the time of focusing.

  The second sub lens unit U12 corresponds to the fifth lens surface to the eighth lens surface in the numerical value example 2, and is configured by two positive lenses. The second sub lens unit U12 moves toward the object side at the time of focusing on a short distance object.

  The third sub lens unit U13 corresponds to the ninth lens surface to the tenth lens surface in the numerical value example 2, and includes one positive meniscus lens. The third sub lens unit U13 moves toward the object side at the time of focusing on a short distance object.

  When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move along different trajectories. Table 1 shows values corresponding to the respective conditional expressions in the present embodiment. The present numerical example satisfies the conditional expressions of the expressions (1) to (12), and achieves good optical performance.

The first lens unit U1, the first sub lens unit U11, the second sub lens unit U12, and the third sub lens unit U13 will be described in the third embodiment as Numerical Embodiment 3.
The first lens unit U1 corresponds to the first lens surface to the eleventh lens surface in the numerical value example 3.

  The first sub lens unit U11 corresponds to the first lens surface to the fifth lens surface in the numerical value example 3, and includes a lens in which a negative lens and a negative lens and a positive lens are bonded in this order from the object side. It is done. The first sub lens unit U11 is fixed at the time of focusing.

  The second sub lens unit U12 corresponds to the sixth lens surface to the ninth lens surface in the numerical value example 3, and includes two positive lenses. Furthermore, the eighth lens surface has an aspheric surface. The second sub lens unit U12 moves toward the object side at the time of focusing on a short distance object.

  The third sub lens unit U13 corresponds to the tenth lens surface to the eleventh lens surface in the numerical value example 3, and is configured by one positive meniscus lens. The third sub lens unit U13 moves toward the object side at the time of focusing on a short distance object.

  When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move along different trajectories. Table 1 shows values corresponding to the respective conditional expressions in the present embodiment. The present numerical example satisfies the conditional expressions of the expressions (1) to (12), and achieves good optical performance.

In the fourth embodiment as Numerical Embodiment 4, the first lens unit U1, the first sub lens unit U11, the second sub lens unit U12, and the third sub lens unit U13 will be described.
The first lens unit U1 corresponds to the first lens surface to the thirteenth lens surface in the numerical value example 4.

  The first sub lens unit U11 corresponds to the first lens surface to the seventh lens surface in the numerical value example 4, and a negative lens, a positive lens, a negative lens and a positive lens are sequentially bonded in this order from the object side It consists of a lens. Furthermore, the fifth lens surface has an aspheric surface. The first sub lens unit U11 is fixed at the time of focusing.

  The second sub lens unit U12 corresponds to the eighth lens surface to the eleventh lens surface in the numerical value example 4, and is configured by two positive lenses. The second sub lens unit U12 moves toward the object side at the time of focusing on a short distance object.

  The third sub lens unit U13 corresponds to the twelfth lens surface to the thirteenth lens surface in the numerical value example 4, and includes one positive meniscus lens. The third sub lens unit U13 is moved to the object side at the time of close in-focus.

  When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move along different trajectories. Table 1 shows values corresponding to the respective conditional expressions in the present embodiment. The present numerical example satisfies the conditional expressions of the expressions (1) to (12), and achieves good optical performance.

In the fifth embodiment as Numerical Embodiment 5, the first lens unit U1, the first sub lens unit U11, the second sub lens unit U12, and the third sub lens unit U13 will be described.
The first lens unit U1 corresponds to the first lens surface to the fourteenth lens surface in the fifth numerical embodiment. The first sub lens unit U11 is fixed at the time of focusing.

  The first sub lens unit U11 corresponds to the first lens surface to the eighth lens surface in the numerical value example 5, and includes a negative lens, a positive lens, a negative lens, and a positive lens in order from the object side . The first sub lens unit U11 is fixed at the time of focusing.

  The second sub lens unit U12 corresponds to the ninth lens surface to the twelfth lens surface in the fifth numerical embodiment, and includes two positive lenses. The second sub lens unit U12 is moved to the object side at the time of short distance focusing.

  The third sub lens unit U13 corresponds to the thirteenth lens surface to the fourteenth lens surface in the fifth numerical embodiment, and includes a single positive meniscus lens. Furthermore, the fourteenth lens surface has an aspheric surface. The third sub lens unit U13 moves toward the object side at the time of focusing on a short distance object.

  When focusing from an infinite distance object to a close distance object, the second sub lens unit and the third sub lens unit move along different trajectories. Table 1 shows values corresponding to the respective conditional expressions in the present embodiment. The present numerical example satisfies the conditional expressions of the expressions (1) to (12), and achieves good optical performance.

  Next, an imaging apparatus using each zoom lens described above as an imaging optical system will be described. FIG. 11 is a schematic view of a main part of an image pickup apparatus (television camera system) using the zoom lens of each embodiment as a photographing optical system. In FIG. 11, reference numeral 101 denotes any one zoom lens of the first to fifth embodiments.

  124 is a camera. The zoom lens 101 is attachable to and detachable from the camera 124. Reference numeral 125 denotes an imaging device configured by mounting the zoom lens 101 on the camera 124. The zoom lens 101 includes a first lens group 114, a second lens group to a fourth lens group that moves during zooming, and a zoom unit 115 that moves on the optical axis during zooming. It has a fifth lens group 116 for imaging. SP is an aperture stop. The fifth lens group 116, which is fixed during zooming and focusing, has a zooming optical system IE which can be inserted and removed from the optical path.

  The zoom unit 115 includes a drive mechanism for driving in the optical axis direction. Reference numerals 117 and 118 denote driving means such as a motor for electrically driving the magnification changing section 115 and the aperture stop SP. Reference numerals 119 and 120 denote detectors such as an encoder, a potentiometer, or a photo sensor for detecting the position on the optical axis of each lens group in the magnification changing unit 115 and the diameter of the aperture stop SP. The drive locus of each lens unit in the magnification changing unit 115 may be either a mechanical locus such as a helicoid or a cam, or an electric locus by an ultrasonic motor or the like. In the camera 124, 109 is a glass block corresponding to an optical filter or color separation prism in the camera 124, 110 is a solid-state imaging device (photoelectric conversion device such as a CCD sensor or CMOS sensor that receives an object image formed by the zoom lens 101) ). Reference numerals 111 and 122 denote CPUs that control various operations of the camera 124 and the zoom lens main body 101. By applying the zoom lens of the present invention to a television camera as described above, an imaging device having high optical performance is realized.

  As mentioned above, although the preferable embodiment of this invention was described, this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

Next, Numerical Embodiments 1 to 5 corresponding to Embodiments 1 to 5 of the present invention will be shown. In each numerical example, i indicates the order of the surface from the object side, ri is the radius of curvature of the i-th surface from the object side, di is the distance between the i-th surface and the i + 1th surface from the object side, ndi and didi It is the refractive index and Abbe number of the i-th optical member. The last three faces are glass blocks such as filters. The focal length, the f-number, and the angle of view respectively represent values when an object at infinity is in focus. BF is a value obtained by air-converting the distance from the final surface of the glass block to the image plane.
The aspheric surface shape is X axis in the optical axis direction, H axis in the direction perpendicular to the optical axis, light traveling direction is positive, R is paraxial radius of curvature, k is conical constant, A3, A4, A5, A6, A7, When A8, A9, A10, A11 and A12 are respectively aspheric coefficients, they are expressed by the following equations.

また、例えば「ｅ−Ｚ」は「×１０^−Ｚ」を意味する。面番号に付された＊印はその面が非球面であることを示している。
各実施例と前述した各条件式との対応を表１に示す。

Also, for example, "e-Z" means " ^x10 -z". The symbol * attached to the surface number indicates that the surface is aspheric.
Table 1 shows the correspondence between each example and each conditional expression described above.

(Numerical Example 1)
Single unit mm
Surface data surface number rd nd vd effective diameter θgF
1 -172.284 3.50 1.83400 37.2 85.84 0.578
2 181.653 5.48 83.20
3-5178.227 9.76 1.43387 95.1 83.25 0.537
4-123.691 0.20 83.45
5 218.184 3.30 1.61340 44.3 81.92 0.563
6 145.505 0.58 80.94
7 150.842 12.19 1.43387 95.1 80.97 0.537
8 -165.824 7.32 80.77
9 104.686 7.49 1.43387 95.1 76.30 0.537
10 764.878 0.20 75.75
11 138.973 7.91 1.43387 95.1 73.30 0.537
12-338.345 0.27 72.72
13 * 61.592 5.72 1.60311 60.6 62.19 0.541
14 129.520 (variable) 61.25
15 * 207.188 1.00 2.00330 28.3 26.44 0.598
16 15.241 5.53 21.48
17-123.867 7.02 1. 80809 22.8 21. 30 0.631
18-13.715 0.75 1.88300 40.8 21.11 0.567
19 107.155 0.30 21.25
20 33.055 2.43 1.80809 22.8 21.60 0.631
21 99.095 (variable) 21.37
22 -84.737 0.75 1.88300 40.8 18.94 0.567
23 36.020 4.50 1.80809 22.8 19.51 0.631
24 -173.980 1.99 20.24
25-27.046 0.75 1.72916 54.7 20.35 0.544
26 -53.248 (variable) 21.26
27 456.111 4.63 1.69680 55.5 27.33 0.543
28 -48.572 (variable) 28.14
29 (stop) 絞 り 0.15 28.71
30 62.385 8.86 1.53172 48.8 29.03 0.563
31 -30.872 1.00 1.95375 32.3 28.82 0.590
32-83.393 33.20 29.41
33 75.027 7.45 1.48749 70.2 29.88 0.530
34 -42.462 3.06 29.47
35 -319.678 1.00 1.88300 40.8 26.21 0.567
36 37.897 4.82 1.50137 56.4 25.70 0.554
37 -92.977 0.18 25.70
38 131.740 6.53 1.51633 64.1 25.46 0.535
39-22.842 1.00 1.88300 40.8 25.12 0.567
40 -181.219 0.19 25.69
41 34.646 6.01 1.48749 70.2 26.08 0.530
42 -165.033 4.50 25.53
43 3 33.00 1.60859 46.4 40.00 0.566
44 13. 13.20 1.51633 64.1 40.00 0.535
45 ∞ 7.05 40.00
Image plane ∞
Aspheric surface data surface 13
K = -2.67808e-002 A 4 = 5.63414e-009 A 6 = 1.24803e-011 A 8 =-1.25491e-01 4 A10 = 9.12508e -018 A12 =-4.00054e-021

15th
K = 1.67708e + 002 A 4 = 8.14709e-006 A 6 = -4.10109e-008 A 8 = 2.81782e-010 A10 =-14.2326e-012 A12 = 2.18646e-015

Various data Zoom ratio 19.54

Focal length 8.00 17.02 33.00 77.99 156.30
F number 1.90 1.90 1.90 1.90 2.70
Half angle of view 34.51 17.91 9.46 4.03 2.02
Image height 5.50 5.50 5.50 5.50 5.50
Lens total length 290.22 290.22 290.22 290.22 290.22
BF 7.05 7.05 7.05 7.05 7.05

d14 0.89 24.51 38.33 49.79 54.74
d21 51.41 24.59 9.53 2.76 5.27
d26 8.58 12.30 14.34 11.48 2.16
d28 4.55 4.02 3.22 1.40 3.25

Entrance pupil position 54.44 107.30 184.77 373.37 639.05
Exit pupil position -705.52 -705.52 -705.52 -705.52 -705.52
Front principal point position 62.35 123.92 216.24 442.82 761.06
Rear principal point position -0.94 -9.97 -25.94 -70.94 -149.24

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 69.21 63.94 41.21 3.27
2 15-15.32. 17.04 0.68-11.26
3 22-46.72 7.99 2.11-3.08
4 27 62.97 4.63 2.47-0.26
5 29 52.28 124.15 48.35 -63.57

Single lens data lens Start surface Focal length
1 1 -104.88
2 3 291.16
3 5-720.80
4 7 183.75
5 9 277.89
6 11 227.63
7 13 187.99
8 15-16.30
9 17 18.36
10 18 -13.65
11 20 59.76
12 22 -28.38
13 23 36.91
14 25 -75.97
15 27 62.97
16 30 39.97
17 31 -51.50
18 33 56.61
19 35 -38.10
20 36 54.14
21 38 38.11
22 39-29.52
23 41 59.12
24 43 0.00
25 44 0.00

(Numerical Example 2)
Unit mm
Surface data surface number rd nd vd effective diameter θgF
1 * -172.160 2.20 1.78470 26.3 76.04 0.614
2 184.695 10.09 73.43
3 846. 787 11. 44 1. 43387 95.1 73. 64 0.537
4 -87.228 8.24 73.70
5 137.626 5.15 1.49700 81.5 69.40 0.537
6 794.028 0.15 68.91
7 104.007 8.81 1.59240 68.3 66.80 0.546
8-301.627 0.15 66.06
9 47.971 5.38 1.61800 63.3 57.50 0.544
10 79.399 (variable) 56.59
11 * 253.975 0.90 1.88300 40.8 23.93 0.567
12 13.753 5.04 19.27
13 -69.251 6.31 1.80809 22.8 19.08 0.631
14 -12.875 0.70 1.88300 40.8 18.77 0.567
15 86.474 0.20 18.68
16 31.349 2.82 1.66680 33 18.86 0.596
17 160.448 (variable) 18.60
18 -22.508 0.70 1.75700 47.8 18.15 0.557
19 57.426 2.77 1.84666 23.8 19.94 0.621
20 -144.007 (variable) 20.65
21 864.391 4.30 1.63854 55.4 25.55 0.549
22 -32.550 0.15 26.18
23-321.201 3.16 1.51633 64.1 26.60 0.535
24-46.397 (variable) 26.80
25 (F-stop) 1. 1.30 25.87
26 63.166 6.10 1.51742 52.4 25.59 0.556
27-24.550 0.90 1. 83481 42.7 25. 32 0.564
28 -471.175 32.40 25.50
29 71.992 5.30 1.49700 81.5 26.90 0.537
30-36.284 0.86 26.93
31 -96.855 1.40 1.83400 37.2 25.93 0.578
32 32.399 5.24 1.48749 70.2 25.54 0.530
33-301.323 1.97 25.78
34 153.591 7.26 1.50137 56.4 26.09 0.554
35 -20.908 1.40 1.83481 42.7 26.13 0.564
36-51.301 0.61 27.34
37 63.358 4.84 1.50137 56.4 27.65 0.554
38 -61.568 4.00 27.48
39 3 33.00 1.60859 46.4 40.00 0.566
40 13. 13.20 1.51633 64.1 40.00 0.535
41 7. 7.61 40.00
Image plane ∞

Aspheric data first surface
K = -8.74449e-001 A4 = -1.41112e-007 A6 = 2.18942e-011 A 8 = -5.95096e-014 A10 = 5.09534e-017 A12 = -1.70689e-020

11th
K = 3.41339e + 002 A 4 = 8.91744e-006 A 6 = -2.32008e-008 A 8 =-5.74675e-011 A10 = 3.04265e-013 A12 =-2.07954e-015

Various data Zoom ratio 17.00

Focal length 8.00 16.58 32.73 60.95 136.00
F number 1.90 1.90 1.89 1.89 2.50
Half angle of view 34.51 18.35 9.54 5.16 2.32
Image height 5.50 5.50 5.50 5.50 5.50
Lens total length 267.49 267.49 267.49 267.49 267.49
BF 7.61 7.61 7.61 7.61

d10 1.20 20.57 33.36 41.37 47.65
d17 47.72 23.62 10.04 4.18 11.42
d20 5.94 9.04 10.74 9.67 1.44
d24 6.61 8.23 7.32 6.25 0.96

Entrance pupil position 48.00 91.23 162.09 274.31 579.51
Exit pupil position 402.46 402.46 402.46 402.46 402.46
Front principal point position 56.16 108.51 197.54 344.67 762.35
Rear principal point position -0.39 -8.98 -25.13 -53.34 -128.40

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 61.00 51.60 35.22 3.12
2 11-13.50 15.97 1.14-9.93
3 18-38.71 3.47-0.46-2.38
4 21 33.92 7.61 3.40 -1.50
5 25 49.10 119.78 55.31-35.03

Single lens data lens Start surface Focal length
1 1 -112.24
2 3 182.49
3 5 333.13
4 7 131.16
5 9 183.35
6 11 -16.40
7 13 18.44
8 14-12.58
9 16 57.51
10 18 -21.17
11 19 48.32.
12 21 49.01
13 23 104.23
14 26 34.84
15 27 -30.88
16 29 49.20
17 31 -28.78
18 32 60.12
19 34 37.07
20 35-42.94
21 37 62.83
22 39 0.00
23 40 0.00

(Numerical Example 3)
Unit mm
Surface data surface number rd nd vd effective diameter θgF
1-302.266 1.80 1.77250 49.6 86.12 0.552
2 191.766 14.11 83.23
3 308.369 1.80 1.80518 25.4 81.67 0.616
4 127.810 16.81 1.43875 94.9 80.61 0.534
5 -107.908 6.35 80.44
6 140.315 5.33 1.43387 95.1 75.43 0.537
7 828.200 0.15 75.04
8 * 84.225 10.60 1.49700 81.5 72.06 0.537
9 -581.982 0.70 71.58
10 59.323 5.87 1.61800 63.3 65.02 0.544
11 107.572 (variable) 64.13
12 * 81.200 0.70 1.88300 40.8 23.70 0.567
13 13.898 5.62 19.40
14-37.570 6.19 1.92286 18.9 19.15 0.650
15-13.890 0.70 1.88300 40.8 19.10 0.567
16 53.772 0.34 18.77
17 27.979 5.41 1.53172 48.8 19.01 0.563
18 -18.846 0.00 18.86
19 -18.846 0.70 1.88300 40.8 18.86 0.567
20-48.026 (variable) 19.65
21-27.935 0.70 1.74320 49.3 21.83 0.553
22 47.341 2.80 1.84666 23.8 24.11 0.621
23 -847.254 (variable) 24.62
24 (F-stop) ∞ 1.68 28.02
25-678.356 4.30 1.65844 50.9 29.29 0.556
26-33.843 0.15 29.79
27 85.959 3.12 1.51633 64.1 30.79 0.535
28-197.123 0.15 30.79
29 120.345 6.31 1.51633 64.1 30.67 0.535
30 -32.357 1.80 1.83400 37.2 30.46 0.578
31 -162.146 35.20 30.83
32 71.410 5.67 1.51633 64.1 30.03 0.535
33-51.641 0.82 29.73
34-124.534 1.80 1.83481 42.7 28.41 0.564
35 28.150 6.35 1.51742 52.4 27.16 0.556
36 -98.066 0.80 27.11
37 97.394 10.71 1.48749 70.2 26.63 0.530
38-26.825 1.80 1.83400 37.2 26.17 0.578
39 -129.109 2.93 26.92
40 76.173 5.56 1.51823 58.9 27.56 0.546
41 -48.851 4.50 27.47
42 3 30.00 1.6034 2 38.0 40.00 0.580
43 16. 16.20 1.51633 64.2 40.00 0.535
44 7. 7.53 40.00
Image plane ∞

Aspheric surface data surface 8
K = -1.18370e-001 A 4 = -1.45100e-008 A 6 = 6.14429e-013 A 8 = -3.84658e-016 A10 = -1.06872e-018 A12 = 4.12629e-022

12th
K = -1.49650e + 001 A4 = 5.25353e-006 A6 = -2.92534e-008 A8 = 3.23465e-010 A10 = -3.44231e-012 A12 = 1.40959e-014
A3 = -9.99333e-007 A5 = -5.91697e-008 A 7 = -4.82122e-010 A 9 = 2.01841e-011 A11 = -1.38838e-013

Various data Zoom ratio 21.00

Focal length 7.80 15.60 31.67 113.88 163.80
F number 1.80 1.80 1.80 1.87 2.69
Half angle of view 35.19 19.42 9.85 2.77 1.92
Image height 5.50 5.50 5.50 5.50 5.50
Lens total length 293.10 293.10 293.10 293.10 293.10
BF 7.53 7.53 7.53 7.53 7.53

d11 0.66 22.49 37.37 52.44 54.66
d20 54.42 29.34 11.77 0.42 2.93
d23 3.96 7.21 9.90 6.19 1.45

Entrance pupil position 54.60 99.71 174.13 446.34 568.43
Exit pupil position 233.36 233.36 233.36 233.36 233.36
Front principal point position 62.67 116.39 210.23 617.65 851.04
Rear principal point position -0.27 -8.07 -24.14 -106.35 -156.27

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 68.20 63.53 43.05 3.45
2 12-13.40 19.65 1.38-12.51
3 21 -42.80 3.50 -0.12 -2.04
4 24 69.68 139.85 84.65-160.73

Single lens data lens Start surface Focal length
1 1-150.92
2 3-269.81
3 4 135.98
4 6 387.49
5 8 148.40
6 10 203.72
7 12 -18.97
8 14 20.94
9 15-12.37
10 17 21.96
11 19 -35.32
12 21-23.43
13 22 52.51
14 25 53.70
15 27 115.94
16 29 49.91
17 30 -48.47
18 32 58.75
19 34 -27.20
20 35 42.82
21 37 44.25
22 38 -40.67
23 40 58.09
24 42 0.00
25 43 0.00

Numerical Embodiment 4
Unit mm
Surface data surface number rd nd vd effective diameter θgF
1 -172.363 3.50 1.83400 37.2 85.87 0.578
2 177.602 5.66 83.19
3-4016.426 9.58 1.43387 95.1 83.24 0.537
4-125.816 0.20 83.46
5 * 215.319 3.30 1.61340 44.3 82.09 0.563
6 150.466 12.49 1.43387 95.1 81.19 0.537
7 -160.063 7.32 80.97
8 110.345 7.44 1.43387 95.1 76.32 0.537
9 1087.934 0.20 75.75
10 137.499 7.85 1.43387 95.1 73.06 0.537
11-350.988 0.25 72.48
12 59.486 5.71 1.60311 60.6 61.77 0.541
13 119.604 (variable) 60.79
14 * 193.628 1.00 2.00330 28.3 26.30 0.598
15 15.226 5.53 21.38
16 -107.287 6.94 1.80809 22.8 21.20 0.631
17-13.626 0.75 1.88300 40.8 21.02 0.567
18 107.507 0.30 21.18
19 33.793 2.47 1.80809 22.8 21.52 0.631
20 111.738 (variable) 21.30
21 -81.007 0.75 1.88300 40.8 18.85 0.567
22 36.793 4.49 1.80809 22.8 19.43 0.631
23 -153.185 1.93 20.16
24-27.072 0.75 1.72916 54.7 20.27 0.544
25-54.813 (variable) 21.19
26 557.223 4.59 1.69680 55.5 27.24 0.543
27 -47.809 (variable) 28.06
28 (F-stop) ∞ 0.15 28.65
29 60.948 8.84 1.53172 48.8 28.98 0.563
30 -31.053 1.00 1.95375 32.3 28.77 0.590
31 -85.967 33.20 29.36
32 70.815 7.59 1.48749 70.2 30.06 0.530
33-43.030 3.03 29.63
34 -693.228 1.00 1.88300 40.8 26.28 0.567
35 36.280 4.79 1.50137 56.4 25.69 0.554
36 -106.305 0.17 25.66
37 141.800 6.51 1.51633 64.1 25.42 0.535
38-22.678 1.00 1.88300 40.8 25.07 0.567
39 -181.538 0.19 25.64
40 34.083 5.98 1.48749 70.2 26.02 0.530
41-185.171 4.50 25.46
42 3 33.00 1.60859 46.4 40.00 0.566
43 13. 13.20 1.51633 64.1 40.00 0.535
44 ∞ 7.02 40.00
Image plane ∞

Aspheric surface data surface 5
K = 3.67410e-001 A 4 = 2.50193e-009 A 6 = 2.23075e-012 A 8 = 2.33642e-016 A10 = -1.47412e-018 A12 = 4.38656e-022

14th
K = 1.63400 e + 002 A 4 = 6.94516 e-006 A 6 =-2.98.717 e-008 A 8 = 8. 27123 e-011 A10 =-1.64348 e-013 A12 =--11.11658 e-015

Various data Zoom ratio 19.54

Focal length 8.00 17.05 33.00 77.99 156.29
F number 1.90 1.89 1.89 1.90 2.70
Half angle of view 34.51 17.88 9.46 4.03 2.02
Image height 5.50 5.50 5.50 5.50 5.50
Lens total length 289.27 289.27 289.27 289.27 289.27
BF 7.02 7.02 7.02 7.02 7.02

d13 0.91 24.44 38.19 49.61 54.55
d20 50.87 24.10 9.40 2.71 4.83
d25 8.49 12.22 14.23 11.40 2.15
d27 4.81 4.31 3.25 1.36 3.55

Entrance pupil position 54.18 107.11 184.62 373.34 637.97
Exit pupil position -657.94 -657.94 -657.94 -657.94 -657.94
Front principal point position 62.09 123.72 215.98 442.19 757.53
Back side principal point position -0.98 -10.03 -25.98 -70.97 -149.27

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 69.12 63.50 40.75 3.09
2 14 -15.24 17.00 0.69 -11.26
3 21 -46.35 7.92 2.05-3.06
4 26 63.12 4.59 2.50-0.21
5 28 52.04 124.16 47.85 -63.74

Single lens data lens Start surface Focal length
1 1 -103.74
2 3 298.39
3 5 -826.11
4 6 180.51
5 8 281.67
6 10 228.25
7 12 188.70
8 14 -16.38
9 16 18.50
10 17-13.58
11 19 58.50
12 21 -28.40
13 22 36.73
14 24 -73.89
15 26 63.12
16 29 39.83
17 30-51.06
18 32 55.95
19 34 -38.79
20 35 54.33
21 37 38.24
22 38 -29.27
23 40 59.38
24 42 0.00
25 43 0.00

Numerical Embodiment 5
Unit mm
Surface data surface number rd nd vd effective diameter θgF
1 -171.020 3.50 1.83400 37.2 85.89 0.578
2 183.224 7.36 83.22
3-637. 084 8. 91 1. 49700 8 1.5 83. 34 0.537
4 -119.380 0.20 83.64
5 205.282 3.30 1.61340 44.3 82.12 0.563
6 149.174 1.02 81.21
7 166.702 11.01 1.43387 95.1 81.23 0.537
8 -188.093 7.29 81.04
9 106.591 7.59 1.43387 95.1 77.17 0.537
10 835.676 0.20 76.65
11 137.960 8.02 1.49700 81.5 74.20 0.537
12-351. 924 0.34 73. 65
13 59.110 5.93 1.49700 81.5 62.39 0.537
14 * 128. 747 (variable) 61. 62
15 * 210.610 1.00 2.00330 28.3 26.76 0.598
16 15.449 5.57 21.79
17 -135.692 6.70 1.80809 22.8 21.63 0.631
18 -14.469 0.75 1.88300 40.8 21.48 0.567
19 85.037 0.30 21.62
20 33.432 2.84 1.80809 22.8 22.03 0.631
21 142.848 (variable) 21.80
22-68.838 0.75 1.88300 40.8 19.04 0.567
23 39.943 4.54 1.80809 22.8 19.67 0.631
24 -116.537 1.79 20.44
25-28.435 0.75 1.72916 54.7 20.54 0.544
26 -57.306 (variable) 21.41
27 485.807 4.49 1.69680 55.5 27.49 0.543
28 -50.293 (variable) 28.25
29 (F-stop) ∞ 0.15 28.80
30 62.740 8.82 1.53172 48.8 29.10 0.563
31-31.342 1.00 1.95375 32.3 28.88 0.590
32-87.734 33.20 29.46
33 75.984 7.45 1.48749 70.2 30.06 0.530
34-42.913 3.03 29.66
35 6591.672 1.00 1.88300 40.8 26.29 0.567
36 35.874 4.75 1.50137 56.4 25.68 0.554
37 -113.339 0.21 25.62
38 157.261 6.34 1.51633 64.1 25.37 0.535
39-22.886 1.00 1.88300 40.8 25.02 0.567
40 -202.578 0.19 25.55
41 34.458 5.92 1.48749 70.2 25.93 0.530
42 -174.241 4.50 25.38
43 3 33.00 1.60859 46.4 40.00 0.566
44 13. 13.20 1.51633 64.1 40.00 0.535
45 ∞ 7.01 40.00
Image plane ∞

Aspheric surface data surface 14
K = -2.03669e-002 A 4 = 1.94344e-008 A 6 =-9.12063e-012 A 8 = 7.55024e-015 A10 = 4.06509e-018 A12 = -2.33605e-021

15th
K = 1.66817e + 002 A 4 = 7.67023e-006 A 6 = -4.175560e-008 A 8 = 3.03747e-010 A10 =-1.52447e-012 A12 = 2.42255e-015

Various data Zoom ratio 19.53

Focal length 8.00 17.08 32.90 77.99 156.22
F number 1.90 1.89 1.89 1.90 2.70
Half angle of view 34.51 17.84 9.49 4.03 2.02
Image height 5.50 5.50 5.50 5.50 5.50
Lens total length 291.87 291.87 291.87 291.87 291.87
BF 7.01 7.01 7.01 7.01 7.01

d14 0.90 24.98 38.90 50.57 55.57
d21 51.77 24.51 9.66 2.83 5.28
d26 9.66 13.48 15.42 12.18 2.16
d28 4.60 3.98 2.96 1.36 3.92

Entrance pupil position 54.67 107.69 184.37 372.50 635.17
Exit pupil position -588.99 -588.99 -588.99 -588.99 -588.99
Front principal point position 62.56 124.28 215.46 440.28 750.45
Rear principal point position -0.99 -10.07 -25.89 -70.98 -149.21

Zoom lens group data group Start surface Focal length Lens configuration length Front principal point position Rear side principal point position
1 1 69.63 64.67 42.02 3.97
2 15-15.87 17.16 0.55-11.57
3 22-47.83 7.83 1.66-3.35
4 27 65.35 4.49 2.40 -0.25
5 29 52.30 123.77 47.57 -62.79

Single lens data lens Start surface Focal length
1 1 -104.92
2 3 293.05
3 5 -905.33
4 7 205.11
5 9 280.00
6 11 199.92
7 13 213.21
8 15-16.52
9 17 19.36
10 18 -13.87
11 20 52.84
12 22 -28.37
13 23 36.92
14 25 -77.93
15 27 65.35
16 30 40.44
17 31 -51.20
18 33 57.25
19 35-40.62
20 36 54.70
21 38 39.02
22 39 -29.13
23 41 59.37
24 43 0.00
25 44 0.00

Table 1: Values of conditional expressions for each numerical example

U1 1st lens group U11 1st sub lens group U12 2nd sub lens group U13 3rd sub lens group U2 2nd lens group U3 3rd lens group U4 4th lens group U5 5th lens group SP aperture DG glass block IP imaging surface

Claims (5)

In order from the object side to the image 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, for zooming At least one zoom lens group that moves, and a lens group that has a positive refractive power that does not move for zooming.
The first lens group moves in order from the object side to the image side, a first sub lens group that does not move for focusing, and moves toward the object side to change the focusing object distance from infinity. The second sub lens group having a power, and the third sub lens group having a positive refractive power, which is moved to the object side to change the focusing object distance from infinity.
The second sub lens unit and the third sub lens unit move along different trajectories in order to change the object distance to be focused from infinity.
The first lens group includes at least one aspheric surface, and
Assuming that the aspheric amount of the aspheric surface at the maximum light beam effective diameter is Δh and the focal length of the first lens unit is f1
5 × 10 ⁻⁵ <| Δh / f 1 | <5 × 10 ⁻³
A zoom lens characterized by satisfying the following conditional expression. The focal length of the first sub lens group is f11, the focal length of the second sub lens group is f12, the focal length of the third sub lens group is f13, and the d-line of the glass material constituting the first lens group is Assuming that the average refractive index is N1, the average Abbe number of the glass material constituting the first lens group is dd1, and the average partial dispersion ratio of the glass material constituting the first lens group is θ1.
−20 <f11 / f1 <−4.0
1.1 <f12 / f1 <2.4
1.9 <f13 / f1 <4.0
1.42 <N1 <1.70
55 <νd1 <90
0.52 <θ1 <0.58
The zoom lens according to claim 1, which satisfies the following conditional expression.
Here, the Abbe number お よ び and the partial dispersion ratio θ are the g-line (wavelength 435.8 nm), the f-line (wavelength 486.1 nm), the d-line (wavelength 587.6 nm), and the c-line (wavelength The refractive index of the glass material at 656.3 nm) is Ng, NF, Nd, and NC respectively, and ν = (Nd-1) / (NF-NC)
θ = (Ng-NF) / (NF-NC)
Is represented by The focal length of the second sub lens group is f12, the focal length of the third sub lens group is f13, and the maximum combined focal length of the second sub lens group and the third sub lens group is (f12 + f13) max, The minimum value of the combined focal length is (f12 + f13) min, the average refractive index at the d-line of the glass material constituting the second sub lens group and the third sub lens group is N2, and the second sub lens group and Assuming that the average Abbe number of the glass material constituting the third sub lens group is dd 2, and the average partial dispersion ratio of the glass material constituting the second sub lens group and the third sub lens group is θ 2
1.0 <f13 / f12 <2.5
1.0 <(f12 + f13) max / (f12 + f13) min <1.1
1.42 <N2 <1.70
63 <d d 2 <95
0.51 <θ2 <0.56
The zoom lens according to claim 1 or 2, wherein the following conditional expression is satisfied.
Here, the Abbe number お よ び and the partial dispersion ratio θ are the g-line (wavelength 435.8 nm), the f-line (wavelength 486.1 nm), the d-line (wavelength 587.6 nm), and the c-line (wavelength The refractive index of the glass material at 656.3 nm) is Ng, NF, Nd, and NC respectively, and ν = (Nd-1) / (NF-NC)
θ = (Ng-NF) / (NF-NC)
Is represented by   The second sub lens group is composed of two convex lenses, and the third sub lens group is composed of a positive meniscus lens having a convex surface facing the object side. The zoom lens according to any one of the above. A zoom lens according to any one of claims 1 to 4;
An imaging element that receives an image formed by the zoom lens;
An imaging apparatus characterized by having:

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