JP2019113700A - Zoom lens and image capturing device - Google Patents

Abstract

To provide a compact high-performance zoom lens which offers a high zoom ratio and good optical performance over an entire zoom range.SOLUTION: A zoom lens comprises a first lens group Ghaving negative refractive power, a second lens group Ghaving positive refractive power, a third lens group Ghaving negative refractive power, and a succeeding lens group Garranged in order from the object side. The zoom lens is configured to keep the first lens group Gstationary with respect to an image plane IMG and move at least the second lens group Gand the third lens group Galong an optical axis to change distances among all the lens groups on the optical axis when zooming from the wide-angle end to the telephoto end. The zoom lens is also configured to satisfy predetermined conditions to be a compact high-performance zoom lens that offers a high zoom ratio and good optical performance over an entire zoom range.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a zoom lens and an imaging device, and more particularly to a zoom lens suitable for an imaging device mounted with a solid-state imaging device such as a CCD and a CMOS, and an imaging device provided with the zoom lens.

  Imaging devices such as single-lens reflex cameras, digital still cameras, video cameras, surveillance cameras, etc., on which solid-state imaging devices such as CCDs and COMS are mounted are rapidly spreading. Along with this, there has been proposed a zoom lens that can be used for an imaging device on which a solid-state imaging device such as a CCD or a CMOS is mounted (see, for example, Patent Document 1).

  The zoom lens disclosed in Patent Document 1 includes, in order from the object side, a first lens group of negative refractive power, a second lens group of positive refractive power, a third lens group of negative refractive power, and a positive lens. Or a fourth lens group having a negative refractive power and a fifth lens group having a positive refractive power, and the first lens group and the fifth lens group are fixed to the imaging surface, and the second lens group This is an optical system that performs zooming from the wide-angle end to the telephoto end by moving the third lens unit and the fourth lens unit.

Patent No. 3226297

  A high-magnification large-aperture zoom lens has been desired as a zoom lens for surveillance cameras, but in recent years, as the solid-state imaging device has been increased in pixel count, high resolution can be used to confirm finer features of the subject ( Expectations for lenses with high performance) are increasing. Along with this, there is a strong demand for a downsized zoom lens having a high zoom ratio and a low cost as well as a high performance optical system.

  However, although the zoom lens disclosed in Patent Document 1 has a wide angle, the variable power ratio is as low as about 4 times, and the needs in recent years have not been sufficiently fulfilled.

  In order to solve the above-mentioned problems of the prior art, the present invention has a high magnification ratio and is small and high-performance capable of maintaining good optical performance over the entire magnification range. It aims at providing a zoom lens. Another object of the present invention is to provide an imaging apparatus provided with a compact, high-performance zoom lens having a high zoom ratio.

In order to solve the problems described above and achieve the object, the zoom lens according to the present invention comprises a first lens group having negative refractive power and a second lens having positive refractive power, which are disposed in order from the object side. And a third lens group having a negative refractive power, and a subsequent lens group, wherein at least the second lens group and the third lens are fixed while the first lens group is fixed to the image plane. The zoom lens is moved from the wide-angle end to the telephoto end by moving the group along the optical axis and changing the distance on the optical axis of each lens group, and the following conditional expression is satisfied. .
(1) 3.5 ≦ | F1 / Fw | ≦ 20.0
(2) 0.7 ≦ | F1 / Ft | ≦ 2.0
(3) 1.9 ≦ | F2 / F3 | ≦ 5.0
Where F1 is the focal length of the first lens group, Fw is the focal length of the zoom lens at the wide angle end, Ft is the focal length of the zoom lens at the telephoto end, F2 is the focal length of the second lens group, and F3 is The focal length of the third lens group is shown.

  According to the present invention, it is possible to provide a small-sized, high-performance zoom lens which has a high zoom ratio and can maintain good optical performance over the entire zoom range.

  According to the present invention, it is possible to provide a small-size, high-performance zoom lens having a high zoom ratio and capable of maintaining good optical performance over the entire zoom range. Play. In addition, it is possible to provide an imaging device provided with a compact, high-performance zoom lens having a high zoom ratio.

FIG. 1 is a cross-sectional view along an optical axis showing a configuration of a zoom lens according to Example 1. 5 is a diagram showing various aberrations of the zoom lens according to Example 1. FIG. FIG. 5 is a cross-sectional view along an optical axis showing a configuration of a zoom lens according to Example 2. FIG. 6 shows various aberrations that occurred in the zoom lens according to Example 2. FIG. 7 is a cross-sectional view along an optical axis showing a configuration of a zoom lens according to Example 3. FIG. 6 shows various aberrations that occurred in the zoom lens according to Example 3. FIG. 10 is a cross-sectional view along an optical axis showing a configuration of a zoom lens according to Example 4. FIG. 7 shows various aberrations that occurred in the zoom lens according to Example 4. It is a figure showing an example of the imaging device provided with the zoom lens concerning the present invention.

  Hereinafter, preferred embodiments of a zoom lens and an imaging device according to the present invention will be described in detail.

  A zoom lens according to the present invention includes a first lens group having negative refractive power, a second lens group having positive refractive power, and a third lens group having negative refractive power, which are disposed in order from the object side And the subsequent lens unit. Then, for zooming from the wide-angle end to the telephoto end, at least the second lens group and the third lens group are moved along the optical axis while the first lens group is fixed to the image plane, It does by changing the spacing on the optical axis of the group.

  In the zoom lens according to the present invention, the second lens unit and the third lens unit play a role of changing magnification. By moving the second lens unit and the third lens unit together at the time of zooming, it is possible to satisfactorily correct focus movement and aberration fluctuation caused at the time of zooming, and it is possible to realize a variable power optical system having high resolving power. In addition, by fixing the first lens group at the time of zooming, the entire length of the optical system can be kept short, and a compact optical system can be realized. Further, since the first lens group tends to be a lens group having a large outer diameter and weight, fixing at the time of zooming makes it possible to simplify the drive mechanism of the optical system. By so doing, aberration correction becomes easy over the entire variable power range, and a compact zoom lens with good optical performance can be realized.

  Furthermore, in the zoom lens according to the present invention, in order to realize a lens having high resolution capable of confirming finer features of the subject in view of the increase in the number of pixels of the solid-state imaging device, various conditions as shown below are set. There is.

First, the zoom lens according to the present invention preferably satisfies the following conditional expression, where F1 is the focal length of the first lens group and Fw is the focal length of the zoom lens at the wide-angle end.
(1) 3.5 ≦ | F1 / Fw | ≦ 20.0

  Conditional expression (1) defines the ratio between the focal length of the first lens unit and the focal length of the zoom lens at the wide-angle end. By satisfying the conditional expression (1), it is possible to maintain good optical performance while realizing a high zoom ratio at the wide-angle end.

  Below the lower limit of conditional expression (1), the refractive power of the first lens unit becomes too strong, which makes it difficult to correct curvature of field and astigmatism, and can not maintain good optical performance. On the other hand, when the upper limit of conditional expression (1) is exceeded, the refractive power of the first lens unit becomes too weak, and the second lens unit and the third lens at the time of zooming are realized to achieve a high zoom ratio. Since the movement amount of the group is increased and the entire length of the optical system is extended, it is difficult to miniaturize the optical system. In addition, when the amount of movement of the lens group that controls zooming increases, the focus movement and aberration fluctuation generated at the time of zooming increase and optical performance deteriorates.

  The lower limit value of the conditional expression (1) is preferably 5.0 or more, more preferably 6.0 or more, still more preferably 7.0 or more, further preferably 8.0 or more, further preferably 8.5. It is preferable to set so as to be 8.9 or more, more preferably. In addition, the upper limit value of the conditional expression (1) is preferably 19.0 or less, more preferably 18.0 or less, further preferably 17.0 or less, further preferably 16.0 or less, further preferably 15.5 In the following, it is more preferable to set so as to be 15.0 or less.

Next, when the focal length of the zoom lens at the telephoto end is Ft and the focal length of the second lens unit is F2, it is preferable to satisfy the following conditional expression.
(2) 0.7 ≦ | F1 / Ft | ≦ 2.0

  Conditional expression (2) defines the ratio between the focal length of the first lens unit and the focal length of the zoom lens at the telephoto end. By satisfying the conditional expression (2), a high zoom ratio can be realized at the telephoto end, and good optical performance can be maintained.

  Below the lower limit of conditional expression (2), the refractive power of the first lens unit becomes too strong, which makes it difficult to correct curvature of field and astigmatism, and can not maintain good optical performance. On the other hand, when the upper limit of conditional expression (2) is exceeded, the refractive power of the first lens unit becomes too weak, and the second lens unit and the third lens at the time of zooming are realized to achieve a high zoom ratio. Since the movement amount of the group is increased and the entire length of the optical system is extended, it is difficult to miniaturize the optical system. In addition, when the amount of movement of the lens group that controls zooming increases, the focus movement and aberration fluctuation generated at the time of zooming increase and optical performance deteriorates.

  The lower limit value of the conditional expression (2) may be set to preferably 0.74 or more, more preferably 0.78 or more. Further, the upper limit value of the conditional expression (2) is preferably set to 1.8 or less, more preferably 1.4 or less.

Further, when the focal length of the zoom lens at the telephoto end is Ft and the focal length of the third lens unit is F3, it is preferable to satisfy the following conditional expression.
(3) 1.9 ≦ | F2 / F3 | ≦ 5.0

  Conditional expression (3) defines the ratio of the focal length of the second lens unit to the focal length of the third lens unit. By satisfying the conditional expression (3), a high zoom ratio can be realized even if the moving amounts of the second lens group and the third lens group at the time of zooming are reduced. As a result, it is possible to maintain good optical performance by suppressing focus movement and aberration fluctuation caused at the time of zooming, and to achieve downsizing of the optical system by keeping the entire length of the optical system short.

  Below the lower limit of conditional expression (3), the refractive power of the second lens unit becomes too strong compared to the third lens unit, and it becomes difficult to correct spherical aberration and axial chromatic aberration in the entire variable power range. Good optical performance can not be maintained. On the other hand, if the upper limit of conditional expression (3) is exceeded, the refractive power of the third lens unit becomes too strong compared to the second lens unit, making it difficult to correct field curvature and astigmatism over the entire zoom range. And can not maintain good optical performance.

  The lower limit value of the conditional expression (3) may be set to preferably 2.0 or more, more preferably 2.5 or more. In addition, the upper limit value of the conditional expression (3) is preferably set to 4.5 or less, more preferably 4.0 or less, and further preferably 3.6 or less.

  By satisfying each of the conditional expressions, the above-described effects can be achieved. And, by satisfying the conditional expressions (1) to (3), it is possible to have a high zoom ratio and to maintain good optical performance over the entire zoom range, in a small size and high performance. Zoom lens can be realized.

Further, in the zoom lens according to the present invention, when the lateral magnification of the third lens group at the telephoto end is β3t, and the lateral magnification of the third lens group at the wide angle end is β3w, it is preferable to satisfy the following conditional expression.
(4) 3.0 ≦ | β3t / β3w | ≦ 9.0

  The conditional expression (4) defines the ratio of the lateral magnification at the wide angle end and the telephoto end of the third lens group, and indicates the ratio of the magnification change of the third lens group. By satisfying the conditional expression (4), a high zoom ratio can be realized even if the moving amount of the second lens group and the third lens group at the time of zooming is reduced. As a result, it is possible to maintain good optical performance by suppressing focus movement and aberration fluctuation caused at the time of zooming, and to achieve downsizing of the optical system by keeping the entire length of the optical system short.

  If the lower limit of conditional expression (4) is exceeded, the rate of change of magnification of the third lens group decreases, so the rate of change of magnification of the other lens groups responsible for changing magnification must be increased. The amount of movement of the other lens units to be managed increases. As a result, it is difficult to miniaturize the optical system. On the other hand, when the upper limit of conditional expression (4) is exceeded, the ratio of magnification change of the third lens unit becomes large, and correction of curvature of field and astigmatism becomes difficult in the entire magnification change range, so that good optical Performance can not be maintained.

  The lower limit value of the conditional expression (4) is preferably set to 3.2 or more, more preferably 3.4 or more. Further, the upper limit value of the conditional expression (4) is preferably 8.0 or less, more preferably 7.0 or less, further preferably 6.5 or less, further preferably 6.0 or less, further preferably 5.5 In the following, it is more preferable to set so as to be 5.0 or less.

  Furthermore, in the zoom lens according to the present invention, the subsequent lens unit is provided with a fourth lens unit having positive refractive power and a fifth lens unit having positive refractive power, which are disposed in order from the object side. It is preferable to comprise.

Furthermore, at the time of zooming, it is preferable to move either the fourth lens unit or the fifth lens unit along the optical axis. At this time, when the lateral magnification of the movable group in the succeeding lens group at the telephoto end is βpt, and the lateral magnification of the movable group in the succeeding lens group at the wide angle end is βpw, it is preferable to satisfy the following conditional expression.
(5) 3.0 ≦ | βpt / βpw | ≦ 10.0

  Conditional expression (5) defines the ratio of the lateral magnification at the wide-angle end and the telephoto end of the movable group in the subsequent lens group, and indicates the ratio of zooming of the movable group. By satisfying the conditional expression (5), it is possible to realize a high zoom ratio while suppressing the moving amount of the movable group at the time of zooming. As a result, it is possible to maintain good optical performance while suppressing focus movement and aberration fluctuation caused at the time of zooming, and to realize downsizing of the optical system by keeping the entire length of the optical system short.

  If the lower limit of conditional expression (5) is exceeded, the rate of change of magnification of the movable group in the subsequent lens group becomes small, so the rates of change of magnification of other lens groups that control zooming must be increased. The amount of movement of the other lens units responsible for changing magnification increases. As a result, particularly when realizing a high zoom ratio, it is difficult to miniaturize the optical system. On the other hand, if the upper limit of conditional expression (5) is exceeded, the rate of magnification change of the movable group in the subsequent lens group becomes large, and correction of field curvature and astigmatism becomes difficult in the entire magnification range. Good optical performance can not be maintained.

  The lower limit value of the conditional expression (5) may be set to preferably 3.4 or more, more preferably 3.9 or more. In addition, the upper limit value of the conditional expression (5) is preferably 9.0 or less, more preferably 8.0 or less, further preferably 7.0 or less, further preferably 6.7 or less, further preferably 6.2. It is good to set so that it becomes the following.

  Note that at the time of zooming, it is preferable that, of the lens groups included in the subsequent lens group, any one of the fourth lens group and the fifth lens group is a movable group. By making any one lens group a movable group, the zooming mechanism can be simplified and the optical system can be miniaturized. Further, in the case where the subsequent lens unit is composed of two lens units, either the fourth lens unit or the fifth lens unit may be a movable unit. When the subsequent lens unit is composed of three or more lens units, and the lens unit (sixth lens unit) disposed on the image side of the fifth lens is fixed on the optical axis during zooming, the fifth lens The fourth lens group is preferably fixed on the optical axis at the time of zooming, and the lens group (sixth lens group) disposed on the image side of the fifth lens is movable at the time of zooming. In this case, either the fourth lens group or the fifth lens group may be a movable group.

  Furthermore, in the zoom lens according to the present invention, it is preferable to configure the first lens group with a single lens. Since the outer diameter of the first lens group tends to be large, it is possible to reduce the weight of the first lens group by configuring the first lens group with a single lens, and to make the first lens group thin. Thus, the entire length of the optical system can be kept short, and the optical system can be miniaturized. In addition, when the first lens group is configured of one lens, the mechanism for holding the first lens group can be simplified. The lens constituting the first lens group may have a negative refractive power, and the shape may be a meniscus shape or a biconcave shape. However, in order to generate strong negative refractive power, it is preferable to be biconcave.

  Furthermore, in the zoom lens according to the present invention, it is preferable to dispose a sixth lens group having positive refractive power on the image surface side of the fifth lens group in the subsequent lens group. In this way, various aberrations such as curvature of field that could not be corrected before passing the fifth lens group can be corrected effectively, and a zoom having higher resolving power over the entire zoom range. It becomes possible to realize a lens.

  Furthermore, in the zoom lens according to the present invention, it is preferable that the distance between the first lens unit and the second lens unit is maximized in the middle region of zooming during zooming from the wide-angle end to the telephoto end. Here, the intermediate range of zooming refers to a region during zooming from the wide-angle end to the telephoto end, and may be any focal length except the wide-angle end and the telephoto end. By arranging the lens group at the time of such magnification change, it becomes possible to realize a high magnification change ratio.

  Furthermore, in the zoom lens according to the present invention, it is preferable that the stop be disposed in the fourth lens group. Furthermore, it is preferable that the stop move together with the fourth lens unit at the time of zooming, or if the fourth lens unit is fixed on the optical axis at the time of zooming, the stop also be fixed. Here, that the diaphragm is arranged in the fourth lens group means that the diaphragm is arranged in any of the lenses disposed on the object side, the image side or the fourth lens group of the fourth lens group. The location to be disposed is not particularly limited as long as it is configured to move or fix along with the fourth lens group along the optical axis direction. By disposing the stop in the fourth lens group, it is possible to suppress aberration fluctuation at the time of zooming, and to achieve high performance.

  Furthermore, in the zoom lens according to the present invention, it is preferable that the third lens unit move to the image side during zooming from the wide angle end to the telephoto end. By arranging the lens group at the time of such magnification change, it becomes possible to realize a high magnification change ratio.

  As described above, according to the present invention, by providing the above configuration, it is possible to have a high zoom ratio and to maintain good optical performance over the entire zoom range. A high performance zoom lens can be realized. This zoom lens is a lens with high optical performance suitable for an imaging device equipped with a solid-state imaging device in which the number of pixels is increased.

  Still another object of the present invention is to provide an imaging device provided with a compact, high-performance zoom lens having a high zoom ratio. In order to achieve this object, the imaging device may be configured to include the zoom lens having the above configuration and a solid-state imaging device that converts an optical image formed by the zoom lens into an electrical signal. By doing this, a high resolution imaging device can be realized.

  Hereinafter, embodiments of the zoom lens according to the present invention will be described in detail with reference to the drawings. The present invention is not limited by the following examples.

FIG. 1 is a cross-sectional view along an optical axis showing a configuration of a zoom lens according to a first example. The zoom lens comprises, in order from the object side, a first lens group G ₁ having a negative refractive power, a second lens group G ₂ having a positive refractive power, a third lens group having a positive refractive power and G _3, the rear lens group G _R, is constituted is arranged. Between the subsequent lens group G _R and the third lens group G _3, an aperture stop STP is disposed to define a predetermined diameter. Between the subsequent lens group G _R and the image plane IMG, a cover glass CG is disposed. The cover glass CG is disposed as needed.

Further, the subsequent lens group G _R is arranged in order from the object side, and the fourth lens group G ₄ having positive refractive power, the fifth lens group G ₅ having positive refractive power, and the positive refractive power a sixth lens group G ₆ having, is constituted is arranged.

The first lens group G ₁ is composed of only the biconcave negative lens L _11.

The second lens group G ₂ is composed of in order from the object side, a negative meniscus lens L ₂₁ with a convex surface on the object side, a biconvex positive lens L _22, a biconvex positive lens L _23, is the placement . The negative meniscus lens L ₂₁ of a biconvex positive lens L _22, are joined. The both surfaces of the biconvex positive lens L _23, aspheric surface is formed.

The third lens group G ₃ is composed of, in order from the object side, a biconcave negative lens L _31, a biconcave negative lens L _32, a biconvex positive lens L _33, a negative meniscus lens L ₃₄ with a convex surface on the image side , Is arranged and configured. The surfaces of the biconcave negative lens L _31, aspheric surface is formed. A biconvex positive lens L ₃₃ and a negative meniscus lens L ₃₄ are cemented.

The fourth lens group G ₄ is composed of in order from the object side, a biconvex positive lens L _41, a negative meniscus lens L ₄₂ having a convex surface directed toward the image side, is the arrangement. The biconvex positive lens L ₄₁ and the negative meniscus lens L ₄₂ are cemented.

The fifth lens group G ₅ is composed of, in order from the object side, a biconvex positive lens L _51, a biconvex positive lens L _52, a biconcave negative lens L _53, a biconvex positive lens L _54, a convex surface on the object side A negative meniscus lens L ₅₅ directed, a biconvex positive lens L _56, and a negative meniscus lens L ₅₇ convex on the image side are disposed. Aspheric surfaces are formed on both surfaces of the biconvex positive lens L ₅₁ . The biconvex positive lens L ₅₂ , the biconcave negative lens L _53, and the biconvex positive lens L ₅₄ are cemented. A negative meniscus lens L ₅₅ of a biconvex positive lens L ₅₆ and a negative meniscus lens L ₅₇ are cemented.

The sixth lens group G ₆ is composed of in order from the object side, a negative meniscus lens L ₆₁ having a convex surface on the object side, a positive meniscus lens L ₆₂ with a convex surface facing the object side, is the arrangement.

In this zoom lens, the first lens unit G ₁ , the fourth lens unit G ₄ , and the sixth lens unit G ₆ are fixed to the image plane IMG at the time of zooming from the wide-angle end to the telephoto end. second lens group G ₂ is moved so as to form a convex locus toward the image plane IMG side along the optical axis, the third lens group G ₃ is monotonically moved from the object side along the optical axis toward the image plane IMG side and, the fifth lens group G ₅ is monotonously moved toward the object side from the image plane IMG side along the optical axis.

  Hereinafter, various numerical data on the zoom lens according to Example 1 will be shown.

(Plane data)
r ₁ = -258.600
d ₁ = 1.300 nd ₁ = 1.8042 d d ₁ = 46.50
r ₂ = 39.170
d ₂ = D (2) (variable)
r ₃ = 56.700
d ₃ = 0.900 nd ₂ = 1.8 548 d d ₂ = 24. 80
r ₄ = 31.260
d ₄ = 5.700 nd ₃ = 1.4970 dd ₃ = 81.61
r ₅ = -79.000
d ₅ = 0.150
r ₆ = 30.850 (aspheric surface)
d ₆ = 5.000 nd ₄ = 1.6935 d d ₄ = 53.20
r ₇ = -96.512 (aspheric surface)
d ₇ = D (7) (variable)
r ₈ = −103.233 (aspheric surface)
d ₈ = 0.600 nd ₅ = 1.8514 d d ₅ = 40.10
r ₉ = 10.784 (aspheric surface)
d ₉ = 3.441
r ₁₀ = -10.850
d ₁₀ = 0.600 nd ₆ = 1.6385 d d ₆ = 55.45
r ₁₁ = 186.000
d ₁₁ = 0.176
r ₁₂ = 76.800
d ₁₂ = 2.310 nd ₇ = 1.9 229 d d ₇ = 20.88
r ₁₃ = -16.960
d ₁₃ = 0.600 nd ₈ = 1.7292 d d ₈ = 54.67
r ₁₄ = -88.880
d ₁₄ = D (14) (variable)
r ₁₅ = ((aperture stop)
d ₁₅ = 0.600
r ₁₆ = 39.720
d ₁₆ = 4.210 nd ₉ = 1.4970 dd ₉ = 81.61
r ₁₇ = -19.300
d ₁₇ = 0.600 nd ₁₀ = 1.8042 dd ₁₀ = 46.50
r ₁₈ = -40.040
d ₁₈ = D (18) (variable)
r ₁₉ = 48.511 (aspheric surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 d d ₁₁ = 53.20
r ₂₀ = -68.078 (aspheric surface)
d ₂₀ = 0.150
r ₂₁ = 15.300
d ₂₁ = 7.440 nd ₁₂ = 1.4970 dd ₁₂ = 81.61
r ₂₂ = -15.300
d ₂₂ = 1.000 nd ₁₃ = 1.8061 d d ₁₃ = 40.73
r ₂₃ = 118.600
d ₂₃ = 3.480 nd ₁₄ = 1.808 1 d d ₁₄ = 22.76
r ₂₄ = -30.260
d ₂₄ = 0.150
r ₂₅ = 26.300
d ₂₅ = 1.000 nd ₁₅ = 2. 0010 n d ₁₅ = 29. 13
r ₂₆ = 8.672
d ₂₆ = 5.290 nd ₁₆ = 1.4970 d d ₁₆ = 81.61
r ₂₇ = -12.864
d ₂₇ = 0.600 nd ₁₇ = 1.6204 d ₁₇ = 60.34
r ₂₈ = -49.000
d ₂₈ = D (28) (variable)
r ₂₉ = 46.000
d ₂₉ == 0.600 nd ₁₈ = 1.9037 d d ₁₈ = 31.31
r ₃₀ = 18.300
d ₃₀ = 2.711
r ₃₁ = 20.440
d ₃₁ = 2.250 nd ₁₉ = 1.6968 d d ₁₉ = 55.46
r ₃₂ = 126.500
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 d d ₂₀ = 64. 14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ((image plane)

Conic constant (k) and the aspherical coefficients _{(A 4, A 6, A} 8, A 10, A 12, A 14)
(Sixth)
k = 0,
A ₄ = −2.8400 × 10 ⁻⁶ , A ₆ = 3.9875 × 10 ⁻⁸ ,
A ₈ = −4.8993 × 10 ⁻¹⁰ , A ₁₀ = 8.6640 × 10 ⁻¹² ,
^{_{A 12 = -6.7380 × 10 -14,}} A 14 = 2.2082 × 10 -16
(Seventh face)
k = 0,
A ₄ = 3.3475 × 10 ⁻⁷ , A ₆ = 1.0920 × 10 ⁻⁸ ,
A ₈ = 3.7294 × 10 ⁻¹⁰ , A ₁₀ = −1.5000 × 10 ⁻¹² ,
^{_{A 12 = -1.2478 × 10 -14,}} A 14 = 1.1593 × 10 -16
(Eighth)
k = 0,
A ₄ = 1.3969 × 10 ⁻⁵ , A ₆ = −1.3224 × 10 ⁻⁷ ,
A ₈ = 6.1860 × 10 ⁻⁹ , A ₁₀ = −1.0476 × 10 ⁻¹⁰ ,
A ₁₂ = 0, A ₁₄ = 0
(9th side)
k = 0,
A ₄ = 4.9520 × 10 ⁻⁶ , A ₆ = −7.5303 × 10 ⁻⁷ ,
A ₈ = 5.6418 × 10 ⁻⁸ , A ₁₀ = −7.6164 × 10 ⁻¹⁰ ,
A ₁₂ = 0, A ₁₄ = 0
(The 19th)
k = 0,
A ₄ = 7.6863 × 10 ⁻⁶ , A ₆ = −1.0741 × 10 ⁻⁸ ,
A ₈ = 2.1915 × 10 ^-9 , A ₁₀ = -1.7507 × 10 ^-11 ,
^{_{A 12 = -1.2945 × 10 -14,}} A 14 = 0
(The 20th)
k = 0,
A ₄ = 2.0382 × 10 ⁻⁵ , A ₆ = −8.9746 × 10 ⁻⁸ ,
A ₈ = 3.1841 × 10 ⁻⁹ , A ₁₀ = −3.1291 × 10 ⁻¹¹ ,
A ₁₂ = 2.2543 × 10 ^-14 , A ₁₄ = 0

(Various data)
Wide-angle end Intermediate focus position Telephoto end focal length 4.28 (Fw) 14.00 48.26 (Ft)
F number 1.35 2.40 3.55
Half angle of view (ω) 56.01 14.82 4.35
D (2) 11.485 16.016 8.960
D (7) 1.432 14.646 27.532
D (14) 25.575 7.830 2.000
D (18) 15.437 7.372 0.700
D (28) 0.701 8.766 15.438

(Zoom lens group data)
Group start focal length 1 1-42.22 (F1)
2 3 26.19 (F2)
3 8 -8.26 (F3)
4 16 60.41
5 19 20.39
6 29 764.80

(Numeric values related to conditional expression (1))
| F1 / Fw | = 9.86

(Numeric values related to conditional expression (2))
| F1 / Ft | = 0.87

(Numeric values related to conditional expression (3))
| F2 / F3 | = 3.16

(Numeric values related to conditional expression (4))
β 3 t (lateral magnification of third lens group G ₃ at telephoto end) = − 0.85
β 3 w (lateral magnification of the third lens group G ₃ at the wide angle end) = − 0.24
| Β3t / β3w | = 3.49

(Numeric values related to conditional expression (5))
β pt (lateral magnification of the movable group (fifth lens group G ₅ ) in the following lens group at the telephoto end) = − 0.86
βpw (lateral magnification of the movable group (fifth lens group G ₅ ) in the succeeding lens group at the wide angle end) = − 0.14
| Βpt / βpw | = 6.09

  FIG. 2 is a diagram showing various aberrations of the zoom lens according to the first example. In the spherical aberration diagram, the vertical axis represents F number (in the figure, indicated by FNO), the solid line represents d line (587.56 nm), the alternate long and short dashed line represents C line (656.28 nm), and the broken line represents F line (486.13 nm). Shows the characteristics of the wavelength corresponding to. In the astigmatism diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line. In the astigmatism diagram, the solid line indicates the characteristic of the sagittal plane (indicated by S in the figure) and the broken line indicates the characteristic of the meridional plane (indicated by M in the figure). In the distortion aberration diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line.

  FIG. 3 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 2. FIG. The optical configuration of the zoom lens according to the present embodiment and the movement of each lens unit at the time of zooming are similar to those of the zoom lens shown in the first embodiment. Therefore, in the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

  Hereinafter, various numerical data on the zoom lens according to Example 2 will be shown.

(Plane data)
r ₁ = -128.642
d ₁ = 1.300 nd ₁ = 1.8042 d d ₁ = 46.50
r ₂ = 86.633
d ₂ = D (2) (variable)
r ₃ = 97.555
d ₃ = 0.900 nd ₂ = 1.8 548 d d ₂ = 24. 80
r ₄ = 40.754
d ₄ = 5.700 nd ₃ = 1.4970 dd ₃ = 81.61
r ₅ = -81.000
d ₅ = 0.150
r ₆ = 33.462 (aspheric surface)
d ₆ = 5.000 nd ₄ = 1.6935 d d ₄ = 53.20
r ₇ = -105.004 (aspheric surface)
d ₇ = D (7) (variable)
r ₈ = −184.258 (aspheric surface)
d ₈ = 0.600 nd ₅ = 1.8514 d d ₅ = 40.10
r ₉ = 9.660 (aspheric surface)
d ₉ = 3.441
r ₁₀ = -12.151
d ₁₀ = 0.600 nd ₆ = 1.6385 d d ₆ = 55.45
r ₁₁ = 67.822
d ₁₁ = 0.176
r ₁₂ = 40.190
d ₁₂ = 2.310 nd ₇ = 1.9 229 d d ₇ = 20.88
r ₁₃ = -21.037
d ₁₃ = 0.600 nd ₈ = 1.7292 d d ₈ = 54.67
r ₁₄ = -106.143
d ₁₄ = D (14) (variable)
r ₁₅ = ((aperture stop)
d ₁₅ = 0.600
r ₁₆ = 35.038
d ₁₆ = 4.210 nd ₉ = 1.4970 dd ₉ = 81.61
r ₁₇ = -22.407
d ₁₇ = 0.600 nd ₁₀ = 1.8042 dd ₁₀ = 46.50
r ₁₈ = -67.185
d ₁₈ = D (18) (variable)
r ₁₉ = 39.835 (aspheric surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 d d ₁₁ = 53.20
r ₂₀ = -80.656 (aspheric surface)
d ₂₀ = 0.150
r ₂₁ = 15.683
d ₂₁ = 7.440 nd ₁₂ = 1.4970 dd ₁₂ = 81.61
r ₂₂ = -15.929
d ₂₂ = 1.000 nd ₁₃ = 1.8061 d d ₁₃ = 40.73
r ₂₃ = 115.784
d ₂₃ = 3.480 nd ₁₄ = 1.808 1 d d ₁₄ = 22.76
r ₂₄ = -31.156
d ₂₄ = 0.150
r ₂₅ = 24.351
d ₂₅ = 1.000 nd ₁₅ = 2. 0010 n d ₁₅ = 29. 13
r ₂₆ = 8.639
d ₂₆ = 5.290 nd ₁₆ = 1.4970 d d ₁₆ = 81.61
r ₂₇ = -13.086
d ₂₇ = 0.600 nd ₁₇ = 1.6204 d ₁₇ = 60.34
r ₂₈ = -43.515
d ₂₈ = D (28) (variable)
r ₂₉ = 15.050
d ₂₉ == 0.600 nd ₁₈ = 1.9037 d d ₁₈ = 31.31
r ₃₀ = 9.741
d ₃₀ = 2.711
r ₃₁ = 15.775
d ₃₁ = 2.250 nd ₁₉ = 1.6968 d d ₁₉ = 55.46
r ₃₂ = 50.681
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 d d ₂₀ = 64. 14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ((image plane)

Conic constant (k) and the aspherical coefficients _{(A 4, A 6, A} 8, A 10, A 12, A 14)
(Sixth)
k = 0,
A ₄ = −2.7204 × 10 ⁻⁶ , A ₆ = 4.0454 × 10 ⁻⁸ ,
A ₈ = −4.6815 × 10 ⁻¹⁰ , A ₁₀ = 8.5225 × 10 ⁻¹² ,
^{_{A 12 = -6.9515 × 10 -14,}} A 14 = 2.2082 × 10 -16
(Seventh face)
k = 0,
A ₄ = 1.0655 × 10 ⁻⁶ , A ₆ = 1.5711 × 10 ⁻⁸ ,
A ₈ = 3.6582 × 10 ⁻¹⁰ , A ₁₀ = −1.8761 × 10 ⁻¹² ,
A ₁₂ = −1.3073 × 10 ⁻¹⁴ , A ₁₄ = 1.1593 × 10 ⁻¹⁶
(Eighth)
k = 0,
A ₄ = −2.3816 × 10 ⁻⁷ , A ₆ = −2.2000 × 10 ⁻⁷ ,
A ₈ = 8.6543 × 10 ⁻⁹ , A ₁₀ = −1.1481 × 10 ⁻¹⁰ ,
A ₁₂ = 0, A ₁₄ = 0
(9th side)
k = 0,
A ₄ = −2.4723 × 10 ⁻⁵ , A ₆ = −1.7377 × 10 ⁻⁶ ,
A ₈ = 7.449 3 × 10 ⁻⁸ , A ₁₀ = −1.1663 × 10 ⁻⁹ ,
A ₁₂ = 0, A ₁₄ = 0
(The 19th)
k = 0,
A ₄ = 4.9385 × 10 ⁻⁶ , A ₆ = −1.2067 × 10 ⁻⁸ ,
A ₈ = 2.2353 × 10 ^-9 , A ₁₀ = -1.8036 × 10 ^-11 ,
^{_{A 12 = -1.2945 × 10 -14,}} A 14 = 0
(The 20th)
k = 0,
A ₄ = 2.2832 × 10 ⁻⁵ , A ₆ = −8.0148 × 10 ⁻⁸ ,
A ₈ = 3.1887 × 10 ⁻⁹ , A ₁₀ = −3.1279 × 10 ⁻¹¹ ,
A ₁₂ = 2.2543 × 10 ^-14 , A ₁₄ = 0

(Various data)
Wide-angle end Intermediate focus position Telephoto end focal length 4.28 (Fw) 14.00 48.27 (Ft)
F number 1.35 2.40 3.55
Half angle of view (ω) 56.77 14.58 4.28
D (2) 12.274 16.396 9.183
D (7) 1.400 15.180 28.408
D (14) 26.225 8 .323 2.308
D (18) 14.205 6.425 0.700
D (28) 0.700 8.480 14.205

(Zoom lens group data)
First group focal length 1 1 -64.20 (F1)
2 3 30.49 (F2)
3 8-8.54 (F3)
4 16 79.94
5 19 19.24
6 29 579.59

(Numeric values related to conditional expression (1))
| F1 / Fw | = 15.00

(Numeric values related to conditional expression (2))
| F1 / Ft | = 1.33

(Numeric values related to conditional expression (3))
| F2 / F3 | = 3.57

(Numeric values related to conditional expression (4))
β 3 t (lateral magnification of the third lens group G ₃ at the telephoto end) = − 0.88
β 3 w (lateral magnification of the third lens group G ₃ at the wide-angle end) = − 0.24
| Β3t / β3w | = 3.66

(Numeric values related to conditional expression (5))
β pt (lateral magnification of the movable group (fifth lens group G ₅ ) in the following lens group at the telephoto end) = − 0.91
βpw (lateral magnification of movable group (fifth lens group G ₅ ) in subsequent lens group at wide angle end) = − 0.21
| Βpt / βpw | = 4.33

  FIG. 4 is a diagram of various aberrations of the zoom lens according to the second example. In the spherical aberration diagram, the vertical axis represents F number (in the figure, indicated by FNO), the solid line represents d line (587.56 nm), the alternate long and short dashed line represents C line (656.28 nm), and the broken line represents F line (486.13 nm). Shows the characteristics of the wavelength corresponding to. In the astigmatism diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line. In the astigmatism diagram, the solid line indicates the characteristic of the sagittal plane (indicated by S in the figure) and the broken line indicates the characteristic of the meridional plane (indicated by M in the figure). In the distortion aberration diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line.

  FIG. 5 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 3. FIG. The optical configuration of the zoom lens according to the present embodiment and the movement of each lens unit at the time of zooming are similar to those of the zoom lens shown in the first embodiment. Therefore, in the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

  Hereinafter, various numerical data on the zoom lens according to Example 3 will be shown.

(Plane data)
r ₁ = −106.965
d ₁ = 1.300 nd ₁ = 1.8042 d d ₁ = 46.50
r ₂ = 43.788
d ₂ = D (2) (variable)
r ₃ = 69.161
d ₃ = 0.900 nd ₂ = 1.8 548 d d ₂ = 24. 80
r ₄ = 35.650
d ₄ = 5.700 nd ₃ = 1.4970 dd ₃ = 81.61
r ₅ = -64.651
d ₅ = 0.150
r ₆ = 34.803 (aspheric surface)
d ₆ = 5.000 nd ₄ = 1.6935 d d ₄ = 53.20
r ₇ = -69.145 (aspheric surface)
d ₇ = D (7) (variable)
r ₈ = -75.672 (aspheric surface)
d ₈ = 0.600 nd ₅ = 1.8514 d d ₅ = 40.10
r ₉ = 11.109 (aspheric surface)
d ₉ = 3.441
r ₁₀ = -11.051
d ₁₀ = 0.600 nd ₆ = 1.6385 d d ₆ = 55.45
r ₁₁ = 72.120
d ₁₁ = 0.176
r ₁₂ = 54.292
d ₁₂ = 2.310 nd ₇ = 1.9 229 d d ₇ = 20.88
r ₁₃ = -21.981
d ₁₃ = 0.600 nd ₈ = 1.7292 d d ₈ = 54.67
r ₁₄ = -31.329
d ₁₄ = D (14) (variable)
r ₁₅ = ((aperture stop)
d ₁₅ = 0.600
r ₁₆ = 38.054
d ₁₆ = 4.210 nd ₉ = 1.4970 dd ₉ = 81.61
r ₁₇ = -30.804
d ₁₇ = 0.600 nd ₁₀ = 1.8042 dd ₁₀ = 46.50
r ₁₈ = -134.701
d ₁₈ = D (18) (variable)
r ₁₉ = 36.618 (aspheric surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 d d ₁₁ = 53.20
r ₂₀ = −102.581 (aspheric surface)
d ₂₀ = 0.150
r ₂₁ = 14.586
d ₂₁ = 7.440 nd ₁₂ = 1.4970 dd ₁₂ = 81.61
r ₂₂ = -16.933
d ₂₂ = 1.000 nd ₁₃ = 1.8061 d d ₁₃ = 40.73
r ₂₃ = 70.311
d ₂₃ = 3.480 nd ₁₄ = 1.808 1 d d ₁₄ = 22.76
r ₂₄ = -34.965
d ₂₄ = 0.150
r ₂₅ = 23.865
d ₂₅ = 1.000 nd ₁₅ = 2. 0010 n d ₁₅ = 29. 13
r ₂₆ = 7.955
d ₂₆ = 5.290 nd ₁₆ = 1.4970 d d ₁₆ = 81.61
r ₂₇ = -15.619
d ₂₇ = 0.600 nd ₁₇ = 1.6204 d ₁₇ = 60.34
r ₂₈ = -66.177
d ₂₈ = D (28) (variable)
r ₂₉ = 13.302
d ₂₉ == 0.600 nd ₁₈ = 1.9037 d d ₁₈ = 31.31
r ₃₀ = 10.303
d ₃₀ = 2.711
r ₃₁ = 23.890
d ₃₁ = 2.250 nd ₁₉ = 1.6968 d d ₁₉ = 55.46
r ₃₂ = 78.008
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 d d ₂₀ = 64. 14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ((image plane)

Conic constant (k) and the aspherical coefficients _{(A 4, A 6, A} 8, A 10, A 12, A 14)
(Sixth)
k = 0,
A ₄ = −2.7204 × 10 ⁻⁶ , A ₆ = 4.0454 × 10 ⁻⁸ ,
A ₈ = −4.6815 × 10 ⁻¹⁰ , A ₁₀ = 8.5225 × 10 ⁻¹² ,
^{_{A 12 = -6.9515 × 10 -14,}} A 14 = 2.2082 × 10 -16
(Seventh face)
k = 0,
A ₄ = 1.0655 × 10 ⁻⁶ , A ₆ = 1.5711 × 10 ⁻⁸ ,
A ₈ = 3.6582 × 10 ⁻¹⁰ , A ₁₀ = −1.8761 × 10 ⁻¹² ,
A ₁₂ = −1.3073 × 10 ⁻¹⁴ , A ₁₄ = 1.1593 × 10 ⁻¹⁶
(Eighth)
k = 0,
A ₄ = −2.3816 × 10 ⁻⁷ , A ₆ = −2.2000 × 10 ⁻⁷ ,
A ₈ = 8.6543 × 10 ⁻⁹ , A ₁₀ = −1.1481 × 10 ⁻¹⁰ ,
A ₁₂ = 0, A ₁₄ = 0
(9th side)
k = 0,
A ₄ = −2.4723 × 10 ⁻⁵ , A ₆ = −1.7377 × 10 ⁻⁶ ,
A ₈ = 7.449 3 × 10 ⁻⁸ , A ₁₀ = −1.1663 × 10 ⁻⁹ ,
A ₁₂ = 0, A ₁₄ = 0
(The 19th)
k = 0,
A ₄ = 4.9385 × 10 ⁻⁶ , A ₆ = −1.2067 × 10 ⁻⁸ ,
A ₈ = 2.2353 × 10 ^-9 , A ₁₀ = -1.8036 × 10 ^-11 ,
^{_{A 12 = -1.2945 × 10 -14,}} A 14 = 0
(The 20th)
k = 0,
A ₄ = 2.2832 × 10 ⁻⁵ , A ₆ = −8.0148 × 10 ⁻⁸ ,
A ₈ = 3.1887 × 10 ⁻⁹ , A ₁₀ = −3.1279 × 10 ⁻¹¹ ,
A ₁₂ = 2.2543 × 10 ^-14 , A ₁₄ = 0

(Various data)
Wide-angle end Intermediate focus position Telephoto end focal length 4.28 (Fw) 14.00 48.27 (Ft)
F number 1.35 2.40 3.55
Half angle of view (ω) 57.86 14.36 4.30
D (2) 8.137 9.742 7.131
D (7) 1.400 18.540 29.821
D (14) 29.415 10.670 2.000
D (18) 15.152 9.306 0.700
D (28) 0.700 6.546 15.152

(Zoom lens group data)
Group start focal length 1 1 -38.49 (F1)
2 3 25.95 (F2)
3 8-9.98 (F3)
4 16 108.72
5 19 20.00
6 29 330.16

(Numeric values related to conditional expression (1))
| F1 / Fw | = 8.99

(Numeric values related to conditional expression (2))
| F1 / Ft | = 0.80

(Numeric values related to conditional expression (3))
| F2 / F3 | = 2.60

(Numeric values related to conditional expression (4))
β 3 t (lateral magnification of the third lens group G ₃ at the telephoto end) = − 0.94
β 3 w (lateral magnification of the third lens group G ₃ at the wide angle end) = − 0.26
| Β3t / β3w | = 3.59

(Numeric values related to conditional expression (5))
β pt (lateral magnification of the movable group (fifth lens group G ₅ ) in the following lens group at the telephoto end) = − 0.96
βpw (lateral magnification of the movable group (fifth lens group G ₅ ) in the succeeding lens group at the wide angle end) = − 0.24
| Βpt / βpw | = 4.05

  FIG. 6 is a diagram of various aberrations of the zoom lens according to the third example. In the spherical aberration diagram, the vertical axis represents F number (in the figure, indicated by FNO), the solid line represents d line (587.56 nm), the alternate long and short dashed line represents C line (656.28 nm), and the broken line represents F line (486.13 nm). Shows the characteristics of the wavelength corresponding to. In the astigmatism diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line. In the astigmatism diagram, the solid line indicates the characteristic of the sagittal plane (indicated by S in the figure) and the broken line indicates the characteristic of the meridional plane (indicated by M in the figure). In the distortion aberration diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line.

FIG. 7 is a cross-sectional view along the optical axis showing the configuration of the zoom lens according to Example 4. The optical configuration of the zoom lens according to the present embodiment and the movement of each lens group at the time of zooming are performed except that a biconvex positive lens L ₄₆₂ is disposed instead of the positive meniscus lens L ₆₂ in the sixth lens group G ₆ . It is similar to the zoom lens shown in Example 1. Therefore, in the present embodiment, the same members as those in the first embodiment are denoted by the same reference numerals, and detailed descriptions thereof will be omitted.

  Hereinafter, various numerical data on the zoom lens according to Example 4 will be shown.

(Plane data)
r ₁ = -87.698
d ₁ = 1.300 nd ₁ = 1.8042 d d ₁ = 46.50
r ₂ = 52. 797
d ₂ = D (2) (variable)
r ₃ = 93.413
d ₃ = 0.900 nd ₂ = 1.8 548 d d ₂ = 24. 80
r ₄ == 37.838
d ₄ = 5.700 nd ₃ = 1.4970 dd ₃ = 81.61
r ₅ = -53.869
d ₅ = 0.150
r ₆ = 33.677 (aspheric surface)
d ₆ = 5.000 nd ₄ = 1.6935 d d ₄ = 53.20
r ₇ = -67.360 (aspheric surface)
d ₇ = D (7) (variable)
r ₈ = -70.691 (aspheric surface)
d ₈ = 0.600 nd ₅ = 1.8514 d d ₅ = 40.10
r ₉ = 10.250 (aspheric surface)
d ₉ = 3.441
r ₁₀ = -11.717
d ₁₀ = 0.600 nd ₆ = 1.6385 d d ₆ = 55.45
r ₁₁ = 80.294
d ₁₁ = 0.176
r ₁₂ = 43.624
d ₁₂ = 2.310 nd ₇ = 1.9 229 d d ₇ = 20.88
r ₁₃ = -24.524
d ₁₃ = 0.600 nd ₈ = 1.7292 d d ₈ = 54.67
r ₁₄ = -46.616
d ₁₄ = D (14) (variable)
r ₁₅ = ((aperture stop)
d ₁₅ = 0.600
r ₁₆ == 36.940
d ₁₆ = 4.210 nd ₉ = 1.4970 dd ₉ = 81.61
r ₁₇ = -37.184
d ₁₇ = 0.600 nd ₁₀ = 1.8042 dd ₁₀ = 46.50
r ₁₈ = -82.098
d ₁₈ = D (18) (variable)
r ₁₉ = 43.988 (aspheric surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 d d ₁₁ = 53.20
r ₂₀ = -92.518 (aspheric surface)
d ₂₀ = 0.150
r ₂₁ = 14.558
d ₂₁ = 7.440 nd ₁₂ = 1.4970 dd ₁₂ = 81.61
r ₂₂ = -17.048
d ₂₂ = 1.000 nd ₁₃ = 1.8061 d d ₁₃ = 40.73
r ₂₃ = 63.629
d ₂₃ = 3.480 nd ₁₄ = 1.808 1 d d ₁₄ = 22.76
r ₂₄ = -33.337
d ₂₄ = 0.150
r ₂₅ = 26.905
d ₂₅ = 1.000 nd ₁₅ = 2. 0010 n d ₁₅ = 29. 13
r ₂₆ = 8.052
d ₂₆ = 5.290 nd ₁₆ = 1.4970 d d ₁₆ = 81.61
r ₂₇ = -14.799
d ₂₇ = 0.600 nd ₁₇ = 1.6204 d ₁₇ = 60.34
r ₂₈ = -49.354
d ₂₈ = D (28) (variable)
r ₂₉ = 18.620
d ₂₉ == 0.600 nd ₁₈ = 1.9037 d d ₁₈ = 31.31
r ₃₀ = 9.463
d ₃₀ = 2.711
r ₃₁ = 15.084
d ₃₁ = 2.250 nd ₁₉ = 1.6968 d d ₁₉ = 55.46
r ₃₂ = -181.440
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 d d ₂₀ = 64. 14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ((image plane)

Conic constant (k) and the aspherical coefficients _{(A 4, A 6, A} 8, A 10, A 12, A 14)
(Sixth)
k = 0,
A ₄ = −4.2932 × 10 ⁻⁶ , A ₆ = 4.0241 × 10 ⁻⁸ ,
A ₈ = −4.7280 × 10 ⁻¹⁰ , A ₁₀ = 8.4476 × 10 ⁻¹² ,
^{_{A 12 = -6.7890 × 10 -14,}} A 14 = 2.1651 × 10 -16
(Seventh face)
k = 0,
A ₄ = 4.1939 × 10 ⁻⁷ , A ₆ = 8.9980 × 10 ⁻⁹ ,
A ₈ = 4.0304 × 10 ⁻¹⁰ , A ₁₀ = −1.6528 × 10 ⁻¹² ,
^{_{A 12 = -1.5116 × 10 -14,}} A 14 = 1.1739 × 10 -16
(Eighth)
k = 0,
A ₄ = −3.9949 × 10 ⁻⁶ , A ₆ = 1.8192 × 10 ⁻⁷ ,
A ₈ = 2.0321 × 10 ⁻⁹ , A ₁₀ = −6.3171 × 10 ⁻¹¹ ,
A ₁₂ = 0, A ₁₄ = 0
(9th side)
k = 0,
A ₄ = −3.8713 × 10 ⁻⁵ , A ₆ = −1.0134 × 10 ⁻⁶ ,
A ₈ = 5.2657 × 10 ⁻⁸ , A ₁₀ = −7.4101 × 10 ⁻¹⁰ ,
A ₁₂ = 0, A ₁₄ = 0
(The 19th)
k = 0,
A ₄ = 4.7575 × 10 ⁻⁶ , A ₆ = −4.5557 × 10 ⁻⁸ ,
A ₈ = 2.1444 × 10 ⁻⁹ , A ₁₀ = −1.7342 × 10 ⁻¹¹ ,
^{_{A 12 = -1.2945 × 10 -14,}} A 14 = 0
(The 20th)
k = 0,
A ₄ = 2.2402 × 10 ⁻⁵ , A ₆ = −9.4619 × 10 ⁻⁸ ,
A ₈ = 3.0257 × 10 ⁻⁹ , A ₁₀ = −2.9738 × 10 ⁻¹¹ ,
A ₁₂ = 2.2543 × 10 ^-14 , A ₁₄ = 0

(Various data)
Wide-angle end Intermediate focus position Telephoto end focal length 4.28 (Fw) 14.00 48.27 (Ft)
F number 1.35 2.40 3.55
Half angle of view (ω) 56.82 14.30 4.22
D (2) 7.363 12.921 9.919
D (7) 1.400 16.097 28.540
D (14) 31.698 11.443 2.000
D (18) 12.486 5.469 1.484
D (28) 0.756 7.773 11.760

(Zoom lens group data)
Group start surface focal length 1 1-40.81 (F1)
2 3 25.79 (F2)
3 8-9.05 (F3)
4 16 67.06
5 19 21.29
6 29 101.02

(Numeric values related to conditional expression (1))
| F1 / Fw | = 9.54

(Numeric values related to conditional expression (2))
| F1 / Ft | = 0.85

(Numeric values related to conditional expression (3))
| F2 / F3 | = 2.85

(Numeric values related to conditional expression (4))
β 3 t (lateral magnification of the third lens group G ₃ at the telephoto end) = − 1.21
β 3 w (lateral magnification of the third lens group G ₃ at the wide angle end) =-0.25
| Β3t / β3w | = 4.90

(Numeric values related to conditional expression (5))
β pt (lateral magnification of the movable group (fifth lens group G ₅ ) in the following lens group at the telephoto end) = − 0.63
βpw (lateral magnification of the movable group (fifth lens group G ₅ ) in the succeeding lens group at the wide angle end) = − 0.11
| Βpt / βpw | = 5.60

  FIG. 8 is a diagram of various aberrations of the zoom lens according to the fourth example. In the spherical aberration diagram, the vertical axis represents F number (in the figure, indicated by FNO), the solid line represents d line (587.56 nm), the alternate long and short dashed line represents C line (656.28 nm), and the broken line represents F line (486.13 nm). Shows the characteristics of the wavelength corresponding to. In the astigmatism diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line. In the astigmatism diagram, the solid line indicates the characteristic of the sagittal plane (indicated by S in the figure) and the broken line indicates the characteristic of the meridional plane (indicated by M in the figure). In the distortion aberration diagram, the vertical axis represents a half angle of view (denoted by ω in the figure), and shows the characteristic of the wavelength corresponding to the d-line.

  The correspondence table of the conditional expressions in each of the above examples is shown below.

In the numerical data in each of the above embodiments, r ₁ , r ₂ ,... Are the radius of curvature of the lens surface, etc., and d ₁ , d ₂ ,. The spacing nd ₁ , nd ₂ ,... Is the refractive index to the d-line (λ = 587.56 nm) of the lens etc., and dd ₁ , dd ₂ ,. Abbe number for 56 nm) is shown. And all units of length are "mm", and all units of angle are "°".

In each of the aspheric surface shapes, the height in the direction perpendicular to the optical axis is h, the displacement in the optical axis direction at height h when the lens surface apex is the origin is X, and the paraxial radius of curvature is R, Let the conical coefficients be k, 4th, 6th, 8th, 10th, 12th and 14th order aspheric coefficients be A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ and A _{14 respectively} , and the image plane direction Is positive, it is expressed by the following equation.

  As described in each of the above embodiments, by satisfying the above respective conditional expressions, it is possible to have a high zoom ratio and to be able to maintain good optical performance over the entire zoom range. Can realize a high-performance zoom lens.

<Example of application>
Next, an example in which the zoom lens according to the present invention is applied to an imaging device will be shown. FIG. 9 is a view showing an example of an imaging device provided with a zoom lens according to the present invention. As shown in FIG. 9, the imaging device 100 includes a lens barrel unit 11 accommodating the zoom lens 10 and a camera body 21 provided with a solid-state imaging device 20. The zoom lens 10 is subjected to magnification change and the like by driving a mechanical mechanism (not shown). Although FIG. 9 shows the zoom lens 10 according to Example 1 (see FIG. 1), even the zoom lenses shown in Examples 2 to 4 can be similarly mounted on the imaging device 100. .

  In the imaging device 100 including the zoom lens 10 and the solid-state imaging device 20, the image plane IMG shown in FIG. 1 corresponds to the imaging surface of the solid-state imaging device 20. As the solid-state imaging device 20, for example, a photoelectric conversion device such as a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) can be used.

  In the imaging device 100, the light incident from the object side of the zoom lens 10 finally forms an image on the imaging surface of the solid-state imaging device 20. Then, the solid-state imaging device 20 photoelectrically converts the received light and outputs the light as an electric signal. The output signal is processed by a signal processing circuit (not shown) to generate a digital image corresponding to the object image. The digital image can be recorded on a recording medium such as a hard disk drive (HDD), a memory card, an optical disk, a magnetic tape, and the like.

  By providing the configuration as shown in FIG. 9, it is possible to realize an imaging device provided with a compact, high-performance zoom lens having a high zoom ratio.

  FIG. 9 shows an example in which the zoom lens according to the present invention is used for a surveillance camera. However, the zoom lens according to the present invention can be used not only for surveillance cameras but also for video cameras, digital still cameras, single-lens reflex cameras, mirrorless single-lens cameras and the like.

  As described above, the zoom lens according to the present invention is useful for a small-sized imaging device on which a solid-state imaging device such as a CCD or a CMOS is mounted, and is particularly suitable for a surveillance camera that requires high optical performance.

G ₁ first lens group G ₂ second lens group G ₃ third lens group G ₄ fourth lens group G ₅ fifth lens group G ₆ sixth lens group G _R subsequent lens group L ₁₁ , L ₃₁ , L ₃₂ , L ₅₃ biconcave negative lens L ₂₁ , L ₃₄ , L ₄₂ , L ₅₅ , L ₅₇ , L ₆₁ negative meniscus lens L ₂₂ , L ₂₃ , L ₃₃ , L ₄₁ , L ₅₁ , L ₅₂ , L ₅₄ , L ₅₆ , L ₄₆₂ biconvex positive lens L ₆₂ positive meniscus lens STP aperture stop CG cover glass IMG image plane 10 zoom lens 11 lens barrel portion 20 solid-state image sensor 21 camera body 100 image pickup device

Claims (7)

A first lens group having negative refractive power, a second lens group having positive refractive power, a third lens group having negative refractive power, and a subsequent lens group, arranged in order from the object side Configured and
At least the second lens group and the third lens group are moved along the optical axis while the first lens group is fixed relative to the image plane, thereby changing the spacing on the optical axis of the respective lens groups To change the magnification from the wide-angle end to the telephoto end.
A zoom lens characterized by satisfying the following conditional expression.
(1) 3.5 ≦ | F1 / Fw | ≦ 20.0
(2) 0.7 ≦ | F1 / Ft | ≦ 2.0
(3) 1.9 ≦ | F2 / F3 | ≦ 5.0
Where F1 is the focal length of the first lens group, Fw is the focal length of the zoom lens at the wide angle end, Ft is the focal length of the zoom lens at the telephoto end, F2 is the focal length of the second lens group, and F3 is The focal length of the third lens group is shown. The zoom lens according to claim 1, which satisfies the following conditional expression.
(4) 3.0 ≦ | β3t / β3w | ≦ 9.0
Here, β3t indicates the lateral magnification of the third lens group at the telephoto end, and β3w indicates the lateral magnification of the third lens group at the wide angle end.   3. The camera according to claim 1, wherein the subsequent lens group includes a fourth lens group having positive refractive power and a fifth lens group having positive refractive power, which are disposed in order from the object side. The zoom lens described in. During zooming, either the fourth lens group or the fifth lens group moves along the optical axis,
The zoom lens according to claim 3, which satisfies the following conditional expression.
(5) 3.0 ≦ | βpt / βpw | ≦ 10.0
Where βpt represents the lateral magnification of the movable group in the subsequent lens group at the telephoto end, and βpw represents the lateral magnification of the movable group in the subsequent lens group at the wide angle end.   The zoom lens according to any one of claims 1 to 4, wherein the first lens group is configured of a single lens.   5. The zoom lens according to claim 3, wherein a sixth lens group having a positive refractive power is disposed on the image surface side of the fifth lens group in the subsequent lens group.   An imaging apparatus comprising: the zoom lens according to any one of claims 1 to 6; and a solid-state imaging device for converting an optical image formed by the zoom lens into an electrical signal.

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