JP6840661B2 - Zoom lens and imaging device - Google Patents

Description

The present invention relates to a zoom lens and an image pickup device, and more particularly to a zoom lens suitable for an image pickup device equipped with a solid-state image pickup element such as a CCD or CMOS, and an image pickup device provided with the zoom lens.

Imaging measures equipped with solid-state image sensors such as CCD and COMS, such as single-lens reflex cameras, digital still cameras, video cameras, and surveillance cameras, are rapidly becoming widespread. Along with this, a zoom lens that can be used in an image pickup device equipped with a solid-state image sensor such as a CCD or CMOS has been proposed (see, for example, Patent Document 1).

The zoom lenses disclosed in Patent Document 1 include a first lens group having a negative refractive force, a second lens group having a positive refractive force, a third lens group having a negative refractive force, and a positive lens group in this order from the object side. Alternatively, the fourth lens group having a negative refractive force and the fifth lens group having a positive refractive force are formed, 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 changes the magnification from the wide-angle end to the telescopic end by moving the third lens group and the fourth lens group.

Japanese Patent No. 3226297

As a zoom lens for a surveillance camera, a high-magnification large-diameter zoom lens has been desired, but in recent years, with the advancement of high pixel count of solid-state image sensors, high resolution (high resolution) that enables more detailed features of the subject to be confirmed ( Expectations for lenses with high performance) are increasing. Along with this, there is a strong demand for high-performance optical systems, miniaturization, high-magnification, and low-cost zoom lenses.

However, although the zoom lens disclosed in Patent Document 1 has a wide angle, it has a low magnification ratio of about 4 times, and has not sufficiently met the needs of recent years.

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

In order to solve the above-mentioned problems and achieve the object, the zoom lenses according to the present invention include a first lens group having a negative refractive power and a second lens having a positive refractive power arranged in order from the object side. It is composed of a group, a third lens group having a negative refractive power, and a succeeding lens group, and at least the second lens group and the third lens while the first lens group is fixed to the image plane. By moving the group along the optical axis and changing the distance on the optical axis of each lens group, the magnification is changed from the wide-angle end to the telescopic end, 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
However, 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 compact, high-performance zoom lens having a high magnification ratio and capable of maintaining good optical performance over the entire magnification range.

According to the present invention, it is possible to provide a compact, high-performance zoom lens having a high magnification ratio and capable of maintaining good optical performance over the entire magnification range. Play. Further, it is possible to provide an image pickup apparatus provided with a compact and high-performance zoom lens having a high magnification ratio.

It is sectional drawing along the optical axis which shows the structure of the zoom lens which concerns on Example 1. FIG. It is a figure of various aberrations of the zoom lens which concerns on Example 1. FIG. It is sectional drawing along the optical axis which shows the structure of the zoom lens which concerns on Example 2. FIG. It is a figure of various aberrations of the zoom lens which concerns on Example 2. FIG. It is sectional drawing along the optical axis which shows the structure of the zoom lens which concerns on Example 3. FIG. It is a figure of various aberrations of the zoom lens which concerns on Example 3. FIG. It is sectional drawing along the optical axis which shows the structure of the zoom lens which concerns on Example 4. FIG. It is a figure of various aberrations of the zoom lens which concerns on Example 4. FIG. It is a figure which shows an example of the image pickup apparatus provided with the zoom lens which concerns on this invention.

Hereinafter, preferred embodiments of the zoom lens and the image pickup apparatus according to the present invention will be described in detail.

The zoom lens according to the present invention includes a first lens group having a negative refractive power, a second lens group having a positive refractive power, and a third lens group having a negative refractive power arranged in order from the object side. And a subsequent lens group. Then, in order to change the magnification 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, and the respective lenses are described. This is done by changing the spacing on the optical axis of the group.

In the zoom lens according to the present invention, the second lens group and the third lens group have a magnification-changing action. By moving both the second lens group and the third lens group at the time of scaling, the focus movement and aberration fluctuations that occur at the time of scaling can be satisfactorily corrected, and a variable magnification optical system having high resolution can be realized. In addition, by fixing the first lens group at the time of magnification change, the total length of the optical system can be kept short, and a small optical system can be realized. Further, since the first lens group tends to be a heavy lens group having a large outer diameter, it is possible to simplify the drive mechanism of the optical system by fixing the lens group at the time of scaling. By doing so, aberration correction becomes easy over the entire variable magnification range, and a compact zoom lens having good optical performance can be realized.

Further, in the zoom lens according to the present invention, in view of increasing the number of pixels of the solid-state image sensor, in order to realize a lens having high resolution capable of confirming more detailed features of the subject, various conditions as shown below are set. There is.

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

The conditional expression (1) is an expression that defines the ratio between the focal length of the first lens group and the focal length of the zoom lens at the wide-angle end. By satisfying the conditional expression (1), good optical performance can be maintained while achieving a high magnification ratio at the wide-angle end.

If it is less than the lower limit in the conditional expression (1), the refractive power of the first lens group becomes too strong, it becomes difficult to correct curvature of field and astigmatism, and good optical performance cannot be maintained. On the other hand, if the upper limit is exceeded in the conditional equation (1), the refractive power of the first lens group becomes too weak, and in order to realize a high magnification ratio, the second lens group and the third lens at the time of magnification change. Since the amount of movement of the group increases and the total length of the optical system increases, it becomes difficult to miniaturize the optical system. Further, when the amount of movement of the lens group that controls the magnification increases, the focus movement and the aberration fluctuation that occur at the time of the magnification increase, and the optical performance deteriorates.

The lower limit of the conditional expression (1) is preferably 5.0 or more, more preferably 6.0 or more, still more preferably 7.0 or more, still more preferably 8.0 or more, still more preferably 8.5. Above, it is preferable to set it so that it is more preferably 8.9 or more. The upper limit of the conditional expression (1) is preferably 19.0 or less, more preferably 18.0 or less, still more preferably 17.0 or less, still more preferably 16.0 or less, still more preferably 15.5. Hereinafter, it is preferable to set it so that it is more preferably 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 group is F2, it is preferable that the following conditional expression is satisfied.
(2) 0.7 ≦ | F1 / Ft | ≦ 2.0

The conditional expression (2) is an expression that defines the ratio between the focal length of the first lens group and the focal length of the zoom lens at the telephoto end. By satisfying the conditional expression (2), good optical performance can be maintained while achieving a high magnification ratio at the telephoto end.

If it is less than the lower limit in the conditional expression (2), the refractive power of the first lens group becomes too strong, it becomes difficult to correct curvature of field and astigmatism, and good optical performance cannot be maintained. On the other hand, if the upper limit is exceeded in the conditional equation (2), the refractive power of the first lens group becomes too weak, and in order to realize a high magnification ratio, the second lens group and the third lens at the time of magnification change. Since the amount of movement of the group increases and the total length of the optical system increases, it becomes difficult to miniaturize the optical system. Further, when the amount of movement of the lens group that controls the magnification increases, the focus movement and the aberration fluctuation that occur at the time of the magnification increase, and the optical performance deteriorates.

The lower limit of the conditional expression (2) is preferably set to 0.74 or more, more preferably 0.78 or more. Further, the upper limit 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 group is F3, it is preferable that the following conditional expression is satisfied.
(3) 1.9 ≤ | F2 / F3 | ≤ 5.0

The conditional expression (3) is an expression that defines the ratio between the focal length of the second lens group and the focal length of the third lens group. By satisfying the conditional expression (3), a high magnification ratio can be realized even if the amount of movement of the second lens group and the third lens group at the time of scaling is reduced. As a result, it is possible to maintain good optical performance by suppressing focus movement and aberration fluctuation that occur at the time of scaling, and to achieve miniaturization of the optical system by keeping the overall length of the optical system short.

If it falls below the lower limit in the conditional equation (3), the refractive power of the second lens group becomes too strong as compared with the third lens group, and it becomes difficult to correct spherical aberration and axial chromatic aberration in the total magnification range. Good optical performance cannot be maintained. On the other hand, if the upper limit is exceeded in the conditional equation (3), the refractive power of the third lens group becomes too strong as compared with the second lens group, and it is difficult to correct curvature of field and astigmatism in the entire magnification range. Therefore, good optical performance cannot be maintained.

The lower limit of the conditional expression (3) is preferably set to 2.0 or more, more preferably 2.5 or more. Further, the upper limit of the conditional expression (3) is preferably set to 4.5 or less, more preferably 4.0 or less, still more preferably 3.6 or less.

By satisfying each conditional expression, the above-mentioned effect can be obtained. Then, by satisfying the conditional expressions (1) to (3), it is possible to have a high magnification ratio and maintain good optical performance over the entire magnification range, which is compact and high performance. Zoom lens can be realized.

Further, in the zoom lens according to the present invention, it is preferable that the following conditional expression is satisfied 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.
(4) 3.0 ≦ | β3t / β3w | ≦ 9.0

The conditional expression (4) is an expression that 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 variable magnification of the third lens group. By satisfying the conditional expression (4), a high magnification ratio can be realized even if the amount of movement of the second lens group and the third lens group at the time of scaling is reduced. As a result, it is possible to maintain good optical performance by suppressing focus movement and aberration fluctuation that occur at the time of scaling, and to achieve miniaturization of the optical system by keeping the overall length of the optical system short.

If it falls below the lower limit in the conditional expression (4), the scaling ratio of the third lens group becomes small, so the scaling ratio of the other lens groups that control the scaling must be increased, and the scaling ratio must be increased. The amount of movement of the other lens groups that control it increases. As a result, it becomes difficult to reduce the size of the optical system. On the other hand, if the upper limit is exceeded in the conditional expression (4), the magnification ratio of the third lens group becomes large, and it becomes difficult to correct curvature of field and astigmatism in the entire magnification range, so that good optics is obtained. Performance cannot be maintained.

The lower limit of the conditional expression (4) is preferably set to 3.2 or more, more preferably 3.4 or more. The upper limit of the conditional expression (4) is preferably 8.0 or less, more preferably 7.0 or less, still more preferably 6.5 or less, still more preferably 6.0 or less, still more preferably 5.5. Hereinafter, it is preferable to set it so that it is more preferably 5.0 or less.

Further, the zoom lens according to the present invention includes a fourth lens group having a positive refractive power and a fifth lens group having a positive refractive power arranged in order from the object side. It is preferable to configure the lens.

Further, at the time of scaling, it is preferable to move either the fourth lens group or the fifth lens group along the optical axis. At this time, when the lateral magnification of the movable group in the trailing lens group at the telephoto end is βpt and the lateral magnification of the movable group in the trailing 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) is an expression that defines the ratio of the lateral magnification between the wide-angle end and the telephoto end of the movable group in the subsequent lens group, and shows the ratio of the variable magnification of the movable group. By satisfying the conditional expression (5), a high scaling ratio can be realized while suppressing the amount of movement of the movable group at the time of scaling. As a result, it is possible to maintain good optical performance by suppressing focus movement and aberration fluctuation that occur during magnification change, and it is possible to keep the overall length of the optical system short and realize miniaturization of the optical system.

If it falls below the lower limit in the conditional expression (5), the ratio of the magnification of the movable group in the subsequent lens group becomes small, so that the ratio of the magnification of the other lens group that controls the magnification must be increased. The amount of movement of other lens groups that control scaling increases. As a result, it becomes difficult to reduce the size of the optical system, especially when trying to achieve a high magnification ratio. On the other hand, if the upper limit is exceeded in the conditional expression (5), the ratio of magnification of the movable group in the subsequent lens group becomes large, and it becomes difficult to correct curvature of field and astigmatism in the entire magnification range. Good optical performance cannot be maintained.

The lower limit of the conditional expression (5) is preferably set to 3.4 or more, more preferably 3.9 or more. The upper limit of the conditional expression (5) is preferably 9.0 or less, more preferably 8.0 or less, still more preferably 7.0 or less, still more preferably 6.7 or less, still more preferably 6.2. It is recommended to set as follows.

At the time of scaling, it is preferable that any one of the fourth lens group and the fifth lens group among the lens groups included in the subsequent lens group is the movable group. By making any one lens group a movable group, the scaling mechanism can be simplified and the optical system can be miniaturized. When the succeeding lens group is composed of two lens groups, either the fourth lens group or the fifth lens group may be a movable group. When the succeeding lens group is composed of three or more lens groups and the lens group (sixth lens group) arranged on the image side of the fifth lens is fixed on the optical axis at the time of magnification change, the fifth lens It is preferable that the group is a movable group, the fourth lens group is fixed on the optical axis at the time of magnification change, and the lens group (sixth lens group) arranged on the image side of the fifth lens is movable at the time of magnification change. In this case, either the 4th lens group or the 5th lens group may be the movable group.

Further, in the zoom lens according to the present invention, it is preferable that the first lens group is composed of one lens. Since the outer diameter of the first lens group tends to be large, by forming the first lens group with one lens, the weight of the first lens group can be reduced and the first lens group can be made thinner. Therefore, the total length of the optical system can be kept short, and the optical system can be miniaturized. Further, since the first lens group is composed 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 a strong negative refractive power, it is preferable to have a biconcave shape.

Further, in the zoom lens according to the present invention, it is preferable to arrange a sixth lens group having a positive refractive power on the image plane side of the fifth lens group in the subsequent lens group. By doing so, it is possible to effectively correct various aberrations such as curvature of field that could not be corrected by the time the lens passes through the fifth lens group, and the zoom has higher resolution over the entire variable magnification range. It becomes possible to realize a lens.

Further, in the zoom lens according to the present invention, it is preferable that the distance between the first lens group and the second lens group is maximized in the intermediate region of the magnification when the magnification is changed from the wide-angle end to the telephoto end. Here, the intermediate region of scaling refers to a region in the middle of scaling from the wide-angle end to the telephoto end, and may be any focal length excluding 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 ratio.

Further, in the zoom lens according to the present invention, it is preferable that the diaphragm is arranged in the fourth lens group. Further, when the diaphragm moves together with the fourth lens group at the time of scaling, or when the fourth lens group is fixed on the optical axis at the time of scaling, it is preferable that the diaphragm is also fixed. Here, when the diaphragm is arranged in the fourth lens group, the diaphragm is arranged on the object side, the image side, or between the lenses arranged in the fourth lens group of the fourth lens group. The location of the lens is not particularly limited as long as it is configured to move or be fixed together with the fourth lens group along the optical axis direction. By arranging the diaphragm in the fourth lens group, it is possible to suppress the aberration fluctuation at the time of magnification change, and it is possible to improve the performance.

Further, in the zoom lens according to the present invention, it is preferable that the third lens group moves to the image side when the magnification is changed 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 ratio.

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

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

Hereinafter, examples 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 to the following examples.

FIG. 1 is a cross-sectional view taken along an optical axis showing the configuration of the zoom lens according to the first embodiment. _{In this zoom lens, the first lens group G 1} having a negative refractive power, the second lens group G ₂ having a positive refractive power, and the third lens group having a positive refractive power are arranged in this order from the object side (not shown). 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 arranged as needed.

Also, the rear lens group G _R, disposed in order from the object side, a fourth lens group G ₄ having a positive refractive power, a fifth lens group G ₅ having a positive refractive power, positive refractive power The sixth lens group G ₆ having the lens group G 6 is arranged and configured.

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

The second lens group G ₂ is configured by arranging _{a negative meniscus lens L 21} having a convex surface facing the object side, a biconvex positive lens L _22, and a biconvex positive lens L _{23 in order from the object side.} .. The negative meniscus lens L ₂₁ and the biconvex positive lens L ₂₂ are joined. Aspherical surfaces are formed on both sides of the biconvex positive lens L _23.

The third lens group G ₃ includes a biconcave negative lens L ₃₁ , a biconcave negative lens L ₃₂ , a biconvex positive lens L _{33, and a negative meniscus lens L 34} with a convex surface facing the image side, in order from the object side. , Are arranged and configured. Aspherical surfaces are formed on both sides of both concave negative lenses L _31. The biconvex positive lens L ₃₃ and the negative meniscus lens L ₃₄ are joined.

The fourth lens group G ₄ is configured by arranging a _{biconvex positive lens L 41 and a negative meniscus lens L 42} with a convex surface facing the image side in order from the object side. The biconvex positive lens L ₄₁ and the negative meniscus lens L ₄₂ are joined.

The fifth lens group G ₅ has a biconvex positive lens L ₅₁ , a biconvex positive lens L ₅₂ , a biconcave negative lens L ₅₃ , a biconvex positive lens L _54, and a convex surface on the object side in order from the object side. A negative meniscus lens L ₅₅ directed toward the image, a biconvex positive lens L _56, and a negative meniscus lens L ₅₇ with a convex surface facing the image side are arranged and configured. Aspherical surfaces are formed on both sides 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 joined. The negative meniscus lens L ₅₅ , the biconvex positive lens L _56, and the negative meniscus lens L ₅₇ are joined.

The sixth lens group G ₆ is configured by arranging _{a negative meniscus lens L 61} having a convex surface facing the object side and a positive meniscus lens L ₆₂ having a convex surface facing the object side in order from the object side.

In this zoom lens, when the magnification is changed from the wide-angle end to the telescopic end, the first lens group G ₁ , the fourth lens group G ₄ , and the sixth lens group G ₆ remain fixed with respect to the image plane IMG. The two lens group G ₂ moves along the optical axis so as to form a convex locus toward the image plane IMG side, and the third lens group G ₃ monotonically moves from the object side to the image plane IMG side along the optical axis. Then, the fifth lens group G ₅ monotonically moves from the image plane IMG side to the object side along the optical axis.

Hereinafter, various numerical data relating to the zoom lens according to the first embodiment will be shown.

(Surface data)
r ₁ = -258.600
d ₁ = _{1.300 nd 1} = 1.8042 ν d ₁ = 46.50
r ₂ = 39.170
d ₂ = D (2) (variable)
r ₃ = 56.700
d ₃ = 0.900 nd ₂ = 1.8548 ν d ₂ = 24.80
r ₄ = 31.260
d ₄ = 5.700 nd ₃ = 1.4970 ν d ₃ = 81.61
r ₅ = -79.000
d ₅ = 0.150
r ₆ = 30.850 (aspherical surface)
d ₆ = 5.000 nd ₄ = 1.6935 ν d ₄ = 53.20
r ₇ = -96.512 (aspherical surface)
d ₇ = D (7) (variable)
r ₈ = -103.233 (aspherical surface)
d ₈ = 0.600 nd ₅ = 1.8514 ν d ₅ = 40.10
r ₉ = 10.784 (aspherical surface)
d ₉ = 3.441
r ₁₀ = -10.850
d ₁₀ = 0.600 nd ₆ = 1.6385 ν d ₆ = 55.45
r ₁₁ = 186.000
d ₁₁ = 0.176
r ₁₂ = 76.800
d ₁₂ = 2.310 nd ₇ = 1.9229 ν d ₇ = 20.88
r ₁₃ = -16.960
d ₁₃ = 0.600 nd ₈ = 1.7292 ν d ₈ = 54.67
r ₁₄ = -88.880
d ₁₄ = D (14) (variable)
r ₁₅ = ∞ (opening aperture)
d ₁₅ = 0.600
r ₁₆ = 39.720
d ₁₆ = 4.210 nd ₉ = 1.4970 ν d ₉ = 81.61
r ₁₇ = -19.300
d ₁₇ = 0.600 nd ₁₀ = 1.8042 ν d ₁₀ = 46.50
r ₁₈ = -40.040
d ₁₈ = D (18) (variable)
r ₁₉ = 48.511 (aspherical surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 ν d ₁₁ = 53.20
r ₂₀ = -68.078 (aspherical surface)
d ₂₀ = 0.150
r ₂₁ = 15.300
d ₂₁ = 7.440 nd ₁₂ = 1.4970 ν d ₁₂ = 81.61
r ₂₂ = -15.300
d ₂₂ = 1.000 nd ₁₃ = 1.8061 ν d ₁₃ = 40.73
r ₂₃ = 118.600
d ₂₃ = 3.480 nd ₁₄ = 1.8081 ν d ₁₄ = 22.76
r ₂₄ = -30.260
d ₂₄ = 0.150
r ₂₅ = 26.300
d ₂₅ = 1.000 nd ₁₅ = 2.0010 ν d ₁₅ = 29.13
r ₂₆ = 8.672
d ₂₆ = 5.290 nd ₁₆ = 1.4970 ν d ₁₆ = 81.61
r ₂₇ = -12.864
d ₂₇ = 0.600 nd ₁₇ = 1.6204 ν 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 ν d ₁₈ = 31.31
r ₃₀ = 18.300
d ₃₀ = 2.711
r ₃₁ = 20.440
d ₃₁ = 2.250 nd ₁₉ = 1.6968 ν d ₁₉ = 55.46
r ₃₂ = 126.500
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 ν d ₂₀ = 64.14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ∞ (image plane)

Conical coefficient (k) and aspherical coefficient (A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , A ₁₄ )
(Sixth page)
k = 0,
A ₄ = -2.8400 x 10 ^-6 , A ₆ = 3.9875 x 10 ^-8 ,
A ₈ = -4.8993 x 10 ^-10 , A ₁₀ = 8.6640 x 10 ^-12 ,
A ₁₂ = -6.7 380 x 10 ^-14 , A ₁₄ = 2.208 2 x 10 ^-16
(7th page)
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 x 10 ^-14 , A ₁₄ = 1.1593 x 10 ^-16
(8th page)
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
(Surface 9)
k = 0,
A ₄ = 4.9520 x 10 ^-6 , A ₆ = -7.5 303 x 10 ^-7 ,
A ₈ = 5.6418 x 10 ^-8 , A ₁₀ = -7.6164 x 10 ^-10 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 19)
k = 0,
A ₄ = 7.6863 × 10 ^-6 , A ₆ = -1.0741 × 10 ^-8 ,
A ₈ = 2.1915 x 10 ^-9 , A ₁₀ = -1.7507 x 10 ^-11 ,
A ₁₂ = -1.2945 x 10 ^-14 , A ₁₄ = 0
(Surface 20)
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 focal length 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 starting surface 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

(Numerical value related to conditional expression (1))
｜ F1 / Fw ｜ ＝ 9.86

(Numerical value related to conditional expression (2))
| F1 / Ft | = 0.87

(Numerical value related to conditional expression (3))
｜ F2 / F3 ｜ ＝ 3.16

(Numerical value related to conditional expression (4))
β3t (horizontal magnification of the third lens group G ₃ at the telephoto end) = -0.85
β3w (horizontal magnification of the third lens group G ₃ at the wide-angle end) = -0.24
| Β3t / β3w | = 3.49

(Numerical value related to conditional expression (5))
βpt (horizontal magnification of the movable group (fifth lens group G ₅ ) in the subsequent lens group at the telephoto end) = -0.86
_{βpw (horizontal magnification of the movable group (fifth lens group G 5} ) in the subsequent lens group at the wide-angle end) = -0.14
｜ βpt / βpw ｜ ＝ 6.09

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

FIG. 3 is a cross-sectional view taken along an optical axis showing the configuration of the zoom lens according to the second embodiment. The optical configuration of the zoom lens according to the present embodiment and the movement of each lens group at the time of magnification change are the same as those of the zoom lens shown in the first embodiment. Therefore, in this embodiment, the same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Hereinafter, various numerical data relating to the zoom lens according to the second embodiment will be shown.

(Surface data)
r ₁ = -128.642
d ₁ = _{1.300 nd 1} = 1.8042 ν d ₁ = 46.50
r ₂ = 86.633
d ₂ = D (2) (variable)
r ₃ = 97.555
d ₃ = 0.900 nd ₂ = 1.8548 ν d ₂ = 24.80
r ₄ = 40.754
d ₄ = 5.700 nd ₃ = 1.4970 ν d ₃ = 81.61
r ₅ = -81.000
d ₅ = 0.150
r ₆ = 33.462 (aspherical surface)
d ₆ = 5.000 nd ₄ = 1.6935 ν d ₄ = 53.20
r ₇ = -105.004 (aspherical surface)
d ₇ = D (7) (variable)
r ₈ = -184.258 (aspherical surface)
d ₈ = 0.600 nd ₅ = 1.8514 ν d ₅ = 40.10
r ₉ = 9.660 (aspherical surface)
d ₉ = 3.441
r ₁₀ = -12.151
d ₁₀ = 0.600 nd ₆ = 1.6385 ν d ₆ = 55.45
r ₁₁ = 67.822
d ₁₁ = 0.176
r ₁₂ = 40.190
d ₁₂ = 2.310 nd ₇ = 1.9229 ν d ₇ = 20.88
r ₁₃ = -21.037
d ₁₃ = 0.600 nd ₈ = 1.7292 ν d ₈ = 54.67
r ₁₄ = -106.143
d ₁₄ = D (14) (variable)
r ₁₅ = ∞ (opening aperture)
d ₁₅ = 0.600
r ₁₆ = 35.038
d ₁₆ = 4.210 nd ₉ = 1.4970 ν d ₉ = 81.61
r ₁₇ = -22.407
d ₁₇ = 0.600 nd ₁₀ = 1.8042 ν d ₁₀ = 46.50
r ₁₈ = -67.185
d ₁₈ = D (18) (variable)
r ₁₉ = 39.835 (aspherical surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 ν d ₁₁ = 53.20
r ₂₀ = -80.656 (aspherical surface)
d ₂₀ = 0.150
r ₂₁ = 15.683
d ₂₁ = 7.440 nd ₁₂ = 1.4970 ν d ₁₂ = 81.61
r ₂₂ = -15.929
d ₂₂ = 1.000 nd ₁₃ = 1.8061 ν d ₁₃ = 40.73
r ₂₃ = 115.784
d ₂₃ = 3.480 nd ₁₄ = 1.8081 ν d ₁₄ = 22.76
r ₂₄ = -31.156
d ₂₄ = 0.150
r ₂₅ = 24.351
d ₂₅ = 1.000 nd ₁₅ = 2.0010 ν d ₁₅ = 29.13
r ₂₆ = 8.639
d ₂₆ = 5.290 nd ₁₆ = 1.4970 ν d ₁₆ = 81.61
r ₂₇ = -13.086
d ₂₇ = 0.600 nd ₁₇ = 1.6204 ν 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 ν d ₁₈ = 31.31
r ₃₀ = 9.471
d ₃₀ = 2.711
r ₃₁ = 15.775
d ₃₁ = 2.250 nd ₁₉ = 1.6968 ν d ₁₉ = 55.46
r ₃₂ = 50.681
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 ν d ₂₀ = 64.14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ∞ (image plane)

Conical coefficient (k) and aspherical coefficient (A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , A ₁₄ )
(Sixth page)
k = 0,
A ₄ = -2.7204 x 10 ^-6 , A ₆ = 4.0454 x 10 ^-8 ,
A ₈ = -4.6815 × 10 ^-10 , A ₁₀ = 8.5225 × 10 ^-12 ,
A ₁₂ = -6.9515 × 10 ^-14 , A ₁₄ = 2.208 2 × 10 ^-16
(7th page)
k = 0,
A ₄ = 1.0655 × 10 ^-6 , A ₆ = 1.5711 × 10 ^-8 ,
A ₈ = 3.6582 x 10 ^-10 , A ₁₀ = -1.8761 x 10 ^-12 ,
A ₁₂ = -1.3073 x 10 ^-14 , A ₁₄ = 1.1593 x 10 ^-16
(8th page)
k = 0,
A ₄ = -2.3816 x 10 ^-7 , A ₆ = -2.2000 x 10 ^-7 ,
A ₈ = 8.6543 × 10 ^-9 , A ₁₀ = -1.1481 × 10 ^-10 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 9)
k = 0,
A ₄ = -2.4723 x 10 ^-5 , A ₆ = -1.7377 x 10 ^-6 ,
A ₈ = 7.4493 × 10 ^-8 , A ₁₀ = -1.1663 × 10 ^-9 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 19)
k = 0,
A ₄ = 4.9385 × 10 ^-6 , A ₆ = -1.2067 × 10 ^-8 ,
A ₈ = 2.2353 x 10 ^-9 , A ₁₀ = -1.8 036 x 10 ^-11 ,
A ₁₂ = -1.2945 x 10 ^-14 , A ₁₄ = 0
(Surface 20)
k = 0,
A ₄ = 2.2832 x 10 ^-5 , A ₆ = -8.0 148 x 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 focal length 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)
Group starting surface Focal length 1 1 -64.20 (F1)
2 3 30.49 (F2)
38 -8.54 (F3)
4 16 79.94
5 19 19.24
6 29 579.59

(Numerical value related to conditional expression (1))
｜ F1 / Fw ｜ ＝ 15.00

(Numerical value related to conditional expression (2))
| F1 / Ft | = 1.33

(Numerical value related to conditional expression (3))
｜ F2 / F3 ｜ ＝ 3.57

(Numerical value related to conditional expression (4))
β3t (horizontal magnification of the third lens group G _{3 at the telephoto end) = -0.88}
β3w (horizontal magnification of the third lens group G _{3 at the wide-angle end) = -0.24}
｜ β3t / β3w ｜ ＝ 3.66

(Numerical value related to conditional expression (5))
βpt (horizontal magnification of the movable group (fifth lens group G ₅ ) in the subsequent lens group at the telephoto end) = -0.91
_{βpw (horizontal magnification of the movable group (fifth lens group G 5} ) in the subsequent lens group at the 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 embodiment. In the spherical aberration diagram, the vertical axis represents the F number (indicated by FNO in the figure), the solid line is the d line (587.56 nm), the alternate long and short dash line is the C line (656.28 nm), and the broken line is the F line (486.13 nm). ) Corresponds to the characteristics of the wavelength. In the astigmatism diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line. In the astigmatism diagram, the solid line indicates the characteristics of the sagittal plane (indicated by S in the figure), and the broken line indicates the characteristics of the meridional plane (indicated by M in the figure). In the distortion diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line.

FIG. 5 is a cross-sectional view taken along an optical axis showing the configuration of the zoom lens according to the third embodiment. The optical configuration of the zoom lens according to the present embodiment and the movement of each lens group at the time of magnification change are the same as those of the zoom lens shown in the first embodiment. Therefore, in this embodiment, the same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Hereinafter, various numerical data relating to the zoom lens according to the third embodiment will be shown.

(Surface data)
r ₁ = -106.965
d ₁ = _{1.300 nd 1} = 1.8042 ν d ₁ = 46.50
r ₂ = 43.788
d ₂ = D (2) (variable)
r ₃ = 69.161
d ₃ = 0.900 nd ₂ = 1.8548 ν d ₂ = 24.80
r ₄ = 35.650
d ₄ = 5.700 nd ₃ = 1.4970 ν d ₃ = 81.61
r ₅ = -64.651
d ₅ = 0.150
r ₆ = 34.803 (aspherical surface)
d ₆ = 5.000 nd ₄ = 1.6935 ν d ₄ = 53.20
r ₇ = -69.145 (aspherical surface)
d ₇ = D (7) (variable)
r ₈ = -75.672 (aspherical surface)
d ₈ = 0.600 nd ₅ = 1.8514 ν d ₅ = 40.10
r ₉ = 11.109 (aspherical surface)
d ₉ = 3.441
r ₁₀ = -11.051
d ₁₀ = 0.600 nd ₆ = 1.6385 ν d ₆ = 55.45
r ₁₁ = 72.120
d ₁₁ = 0.176
r ₁₂ = 54.292
d ₁₂ = 2.310 nd ₇ = 1.9229 ν d ₇ = 20.88
r ₁₃ = -21.981
d ₁₃ = 0.600 nd ₈ = 1.7292 ν d ₈ = 54.67
r ₁₄ = -31.329
d ₁₄ = D (14) (variable)
r ₁₅ = ∞ (opening aperture)
d ₁₅ = 0.600
r ₁₆ = 38.054
d ₁₆ = 4.210 nd ₉ = 1.4970 ν d ₉ = 81.61
r ₁₇ = -30.804
d ₁₇ = 0.600 nd ₁₀ = 1.8042 ν d ₁₀ = 46.50
r ₁₈ = -134.701
d ₁₈ = D (18) (variable)
r ₁₉ = 36.618 (aspherical surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 ν d ₁₁ = 53.20
r ₂₀ = -102.581 (aspherical surface)
d ₂₀ = 0.150
r ₂₁ = 14.586
d ₂₁ = 7.440 nd ₁₂ = 1.4970 ν d ₁₂ = 81.61
r ₂₂ = -16.933
d ₂₂ = 1.000 nd ₁₃ = 1.8061 ν d ₁₃ = 40.73
r ₂₃ = 70.31
d ₂₃ = 3.480 nd ₁₄ = 1.8081 ν d ₁₄ = 22.76
r ₂₄ = -34.965
d ₂₄ = 0.150
r ₂₅ = 23.865
d ₂₅ = 1.000 nd ₁₅ = 2.0010 ν d ₁₅ = 29.13
r ₂₆ = 7.955
d ₂₆ = 5.290 nd ₁₆ = 1.4970 ν d ₁₆ = 81.61
r ₂₇ = -15.619
d ₂₇ = 0.600 nd ₁₇ = 1.6204 ν 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 ν d ₁₈ = 31.31
r ₃₀ = 10.303
d ₃₀ = 2.711
r ₃₁ = 23.890
d ₃₁ = 2.250 nd ₁₉ = 1.6968 ν d ₁₉ = 55.46
r ₃₂ = 78.008
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 ν d ₂₀ = 64.14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ∞ (image plane)

Conical coefficient (k) and aspherical coefficient (A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , A ₁₄ )
(Sixth page)
k = 0,
A ₄ = -2.7204 x 10 ^-6 , A ₆ = 4.0454 x 10 ^-8 ,
A ₈ = -4.6815 × 10 ^-10 , A ₁₀ = 8.5225 × 10 ^-12 ,
A ₁₂ = -6.9515 × 10 ^-14 , A ₁₄ = 2.208 2 × 10 ^-16
(7th page)
k = 0,
A ₄ = 1.0655 × 10 ^-6 , A ₆ = 1.5711 × 10 ^-8 ,
A ₈ = 3.6582 x 10 ^-10 , A ₁₀ = -1.8761 x 10 ^-12 ,
A ₁₂ = -1.3073 x 10 ^-14 , A ₁₄ = 1.1593 x 10 ^-16
(8th page)
k = 0,
A ₄ = -2.3816 x 10 ^-7 , A ₆ = -2.2000 x 10 ^-7 ,
A ₈ = 8.6543 × 10 ^-9 , A ₁₀ = -1.1481 × 10 ^-10 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 9)
k = 0,
A ₄ = -2.4723 x 10 ^-5 , A ₆ = -1.7377 x 10 ^-6 ,
A ₈ = 7.4493 × 10 ^-8 , A ₁₀ = -1.1663 × 10 ^-9 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 19)
k = 0,
A ₄ = 4.9385 × 10 ^-6 , A ₆ = -1.2067 × 10 ^-8 ,
A ₈ = 2.2353 x 10 ^-9 , A ₁₀ = -1.8 036 x 10 ^-11 ,
A ₁₂ = -1.2945 x 10 ^-14 , A ₁₄ = 0
(Surface 20)
k = 0,
A ₄ = 2.2832 x 10 ^-5 , A ₆ = -8.0 148 x 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 focal length 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 starting surface Focal length 1 1 -38.49 (F1)
2 3 25.95 (F2)
38 -9.98 (F3)
4 16 108.72
5 19 20.00
6 29 330.16

(Numerical value related to conditional expression (1))
｜ F1 / Fw ｜ ＝ 8.99

(Numerical value related to conditional expression (2))
| F1 / Ft | = 0.80

(Numerical value related to conditional expression (3))
｜ F2 / F3 ｜ ＝ 2.60

(Numerical value related to conditional expression (4))
β3t (horizontal magnification of the third lens group G _{3 at the telephoto end) = -0.94}
β3w (horizontal magnification of the third lens group G _{3 at the wide-angle end) = -0.26}
｜ β3t / β3w ｜ ＝ 3.59

(Numerical value related to conditional expression (5))
βpt (horizontal magnification of the movable group (fifth lens group G ₅ ) in the subsequent lens group at the telephoto end) = -0.96
_{βpw (horizontal magnification of the movable group (fifth lens group G 5} ) in the subsequent 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 embodiment. In the spherical aberration diagram, the vertical axis represents the F number (indicated by FNO in the figure), the solid line is the d line (587.56 nm), the alternate long and short dash line is the C line (656.28 nm), and the broken line is the F line (486.13 nm). ) Corresponds to the characteristics of the wavelength. In the astigmatism diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line. In the astigmatism diagram, the solid line indicates the characteristics of the sagittal plane (indicated by S in the figure), and the broken line indicates the characteristics of the meridional plane (indicated by M in the figure). In the distortion diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line.

FIG. 7 is a cross-sectional view taken along an optical axis showing the configuration of the zoom lens according to the fourth embodiment. The optical configuration of the zoom lens and the movement of each lens group at the time of magnification change according to this embodiment are carried out except that the biconvex positive lens L ₄₆₂ is arranged in place of the positive meniscus lens L _{62 in the sixth lens group G 6.} This is the same as the zoom lens shown in Example 1. Therefore, in this embodiment, the same members as those in the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted.

Hereinafter, various numerical data relating to the zoom lens according to the fourth embodiment will be shown.

(Surface data)
r ₁ = -87.698
d ₁ = _{1.300 nd 1} = 1.8042 ν d ₁ = 46.50
r ₂ = 52.797
d ₂ = D (2) (variable)
r ₃ = 93.413
d ₃ = 0.900 nd ₂ = 1.8548 ν d ₂ = 24.80
r ₄ = 37.838
d ₄ = 5.700 nd ₃ = 1.4970 ν d ₃ = 81.61
r ₅ = -53.869
d ₅ = 0.150
r ₆ = 33.677 (aspherical surface)
d ₆ = 5.000 nd ₄ = 1.6935 ν d ₄ = 53.20
r ₇ = -67.360 (aspherical surface)
d ₇ = D (7) (variable)
r ₈ = -70.691 (aspherical surface)
d ₈ = 0.600 nd ₅ = 1.8514 ν d ₅ = 40.10
r ₉ = 10.250 (aspherical surface)
d ₉ = 3.441
r ₁₀ = -11.717
d ₁₀ = 0.600 nd ₆ = 1.6385 ν d ₆ = 55.45
r ₁₁ = 80.294
d ₁₁ = 0.176
r ₁₂ = 43.624
d ₁₂ = 2.310 nd ₇ = 1.9229 ν d ₇ = 20.88
r ₁₃ = -24.524
d ₁₃ = 0.600 nd ₈ = 1.7292 ν d ₈ = 54.67
r ₁₄ = -46.616
d ₁₄ = D (14) (variable)
r ₁₅ = ∞ (opening aperture)
d ₁₅ = 0.600
r ₁₆ = 36.940
d ₁₆ = 4.210 nd ₉ = 1.4970 ν d ₉ = 81.61
r ₁₇ = -37.184
d ₁₇ = 0.600 nd ₁₀ = 1.8042 ν d ₁₀ = 46.50
r ₁₈ = -82.098
d ₁₈ = D (18) (variable)
r ₁₉ = 43.988 (aspherical surface)
d ₁₉ = 3.200 nd ₁₁ = 1.6935 ν d ₁₁ = 53.20
r ₂₀ = -92.518 (aspherical surface)
d ₂₀ = 0.150
r ₂₁ = 14.558
d ₂₁ = 7.440 nd ₁₂ = 1.4970 ν d ₁₂ = 81.61
r ₂₂ = -17.048
d ₂₂ = 1.000 nd ₁₃ = 1.8061 ν d ₁₃ = 40.73
r ₂₃ = 63.629
d ₂₃ = 3.480 nd ₁₄ = 1.8081 ν d ₁₄ = 22.76
r ₂₄ = -33.337
d ₂₄ = 0.150
r ₂₅ = 26.905
d ₂₅ = 1.000 nd ₁₅ = 2.0010 ν d ₁₅ = 29.13
r ₂₆ = 8.052
d ₂₆ = 5.290 nd ₁₆ = 1.4970 ν d ₁₆ = 81.61
r ₂₇ = -14.799
d ₂₇ = 0.600 nd ₁₇ = 1.6204 ν 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 ν d ₁₈ = 31.31
r ₃₀ = 9.463
d ₃₀ = 2.711
r ₃₁ = 15.084
d ₃₁ = 2.250 nd ₁₉ = 1.6968 ν d ₁₉ = 55.46
r ₃₂ = -181.440
d ₃₂ = 4.400
r ₃₃ = ∞
d ₃₃ = 1.000 nd ₂₀ = 1.5163 ν d ₂₀ = 64.14
r ₃₄ = ∞
d ₃₄ = 1.000
r ₃₅ = ∞ (image plane)

Conical coefficient (k) and aspherical coefficient (A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , A ₁₄ )
(Sixth page)
k = 0,
A ₄ = -4.2932 x 10 ^-6 , A ₆ = 4.0241 x 10 ^-8 ,
A ₈ = -4.7280 x 10 ^-10 , A ₁₀ = 8.4476 x 10 ^-12 ,
A ₁₂ = -6.7890 x 10 ^-14 , A ₁₄ = 2.165 1 x 10 ^-16
(7th page)
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 x 10 ^-14 , A ₁₄ = 1.1739 x 10 ^-16
(8th page)
k = 0,
A ₄ = -3.9949 x 10 ^-6 , A ₆ = 1.8192 x 10 ^-7 ,
A ₈ = 2.0321 x 10 ^-9 , A ₁₀ = -6.3171 x 10 ^-11 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 9)
k = 0,
A ₄ = -3.8713 x 10 ^-5 , A ₆ = -1.0134 x 10 ^-6 ,
A ₈ = 5.2657 × 10 ^-8 , A ₁₀ = -7.4101 × 10 ^-10 ,
A ₁₂ = 0, A ₁₄ = 0
(Surface 19)
k = 0,
A ₄ = 4.7575 x 10 ^-6 , A ₆ = -4.5557 x 10 ^-8 ,
A ₈ = 2.1444 × 10 ^-9 , A ₁₀ = -1.7342 × 10 ^-11 ,
A ₁₂ = -1.2945 x 10 ^-14 , A ₁₄ = 0
(Surface 20)
k = 0,
A ₄ = 2.2402 x 10 ^-5 , A ₆ = -9.4619 x 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 focal length 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 starting surface Focal length 1 1 -40.81 (F1)
2 3 25.79 (F2)
38 -9.05 (F3)
4 16 67.06
5 19 21.29
6 29 101.02

(Numerical value related to conditional expression (1))
｜ F1 / Fw ｜ ＝ 9.54

(Numerical value related to conditional expression (2))
| F1 / Ft | = 0.85

(Numerical value related to conditional expression (3))
｜ F2 / F3 ｜ ＝ 2.85

(Numerical value related to conditional expression (4))
β3t (horizontal magnification of third lens group G _{3 at the telephoto end) = -1.21}
β3w (horizontal magnification of _{third lens group G 3} at wide-angle end) = -0.25
| Β3t / β3w | = 4.90

(Numerical value related to conditional expression (5))
βpt (horizontal magnification of the movable group (fifth lens group G ₅ ) in the subsequent lens group at the telephoto end) = -0.63
_{βpw (horizontal magnification of the movable group (fifth lens group G 5} ) in the subsequent 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 embodiment. In the spherical aberration diagram, the vertical axis represents the F number (indicated by FNO in the figure), the solid line is the d line (587.56 nm), the alternate long and short dash line is the C line (656.28 nm), and the broken line is the F line (486.13 nm). ) Corresponds to the characteristics of the wavelength. In the astigmatism diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line. In the astigmatism diagram, the solid line indicates the characteristics of the sagittal plane (indicated by S in the figure), and the broken line indicates the characteristics of the meridional plane (indicated by M in the figure). In the distortion diagram, the vertical axis represents a half angle of view (indicated by ω in the figure), and shows the characteristics of the wavelength corresponding to the d line.

The correspondence table of the conditional expression in each of the above Examples is shown below.

In the numerical data in each of the above examples, r ₁ , r ₂ , ... Are the radius of curvature of the lens surface, etc., and d ₁ , d ₂ , ... Are the wall thickness of the lens, etc. or their surfaces. The interval, nd ₁ , nd ₂ , ... Is the refractive index for the d line (λ = 587.56 nm) of the _{lens, etc., and ν d 1} , ν d ₂ , ... Is the d line of the lens, etc. (λ = 587. The Abbe number with respect to 56 nm) is shown. The unit of length is "mm", and the unit of angle is "°".

Further, in each of the aspherical shapes, the height in the direction perpendicular to the optical axis is h, the amount of displacement in the optical axis direction at the height h when the lens surface top is the origin is X, and the radius of curvature of the paraxial axis is R. The conical coefficients are k, the 4th, 6th, 8th, 10th, 12th, and 14th aspherical coefficients are A ₄ , A ₆ , A ₈ , A ₁₀ , A ₁₂ , and A ₁₄ , respectively, and the image plane direction. When is positive, it is expressed by the following formula.

As shown in each of the above examples, by satisfying each of the above conditional expressions, it is possible to have a high magnification ratio and maintain good optical performance over the entire magnification range. , A high-performance zoom lens can be realized.

<Application example>
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 diagram showing an example of an image pickup apparatus provided with a zoom lens according to the present invention. As shown in FIG. 9, the image pickup device 100 includes a lens barrel portion 11 accommodating a zoom lens 10 and a camera body 21 including a solid-state image pickup element 20. The zoom lens 10 is subjected to scaling and the like by driving a mechanical mechanism (not shown). Although FIG. 9 shows the zoom lens 10 of the first embodiment (see FIG. 1), the zoom lens shown in the second to fourth embodiments can be mounted on the image pickup apparatus 100 in the same manner. ..

In the image pickup apparatus 100 including the zoom lens 10 and the solid-state image sensor 20, the image plane IMG shown in FIG. 1 corresponds to the image pickup surface of the solid-state image sensor 20. As the solid-state image sensor 20, for example, a photoelectric conversion element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal Oxide Semiconductor) can be used.

In the image pickup apparatus 100, the light incident from the object side of the zoom lens 10 is finally imaged on the image pickup surface of the solid-state image pickup device 20. Then, the solid-state image sensor 20 photoelectrically converts the received light and outputs it as an electric signal. This output signal is arithmetically 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 an HDD (Hard Disk Drive), a memory card, an optical disk, or a magnetic tape.

By providing the configuration as shown in FIG. 9, it is possible to realize an image pickup apparatus equipped with a compact, high-performance zoom lens having a high magnification ratio.

FIG. 9 shows an example in which the zoom lens according to the present invention is used as 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 image sensor equipped with a solid-state image sensor such as a CCD or CMOS, and is particularly suitable for a surveillance camera that requires high optical performance.

G ₁ first lens group G ₂ the second lens group G ₃ third lens group G ₄ fourth lens group G ₅ the fifth lens group G ₆ sixth lens group G _R subsequent lens unit _{L 11, L 31, L 32} , L ₅₃ Double concave 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 aperture CG Cover glass IMG image plane 10 Zoom lens 11 Lens lens barrel 20 Solid-state imager 21 Camera body 100 Imager

Claims (5)

From the first lens group having a negative refractive power, the second lens group having a positive refractive power, the third lens group having a negative refractive power, and the succeeding lens group arranged in order from the object side. Configured
The subsequent lens group consists of a fourth lens group having a positive refractive power, a fifth lens group having a positive refractive power, and a sixth lens group having a positive refractive power arranged in order from the object side. Naru,
While the first lens group is fixed to the image plane, at least the second lens group and the third lens group are moved along the optical axis to change the distance on the optical axis of each lens group. Scales 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
However, 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, wherein the zoom lens satisfies the conditional expression shown below.
(4) 3.0 ≦ | β3t / β3w | ≦ 9.0
However, 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. At the time of scaling, either the 4th lens group or the 5th lens group moves along the optical axis.
The zoom lens according to claim 1 or 2 , wherein the zoom lens satisfies the conditional expression shown below.
(5) 3.0 ≦ | βpt / βpw | ≦ 10.0
However, βpt indicates the lateral magnification of the movable group in the succeeding lens group at the telephoto end, and βpf indicates 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 3 , wherein the first lens group is composed of one lens. An image pickup apparatus comprising the zoom lens according to any one of claims 1 to 4 and a solid-state image pickup element that converts an optical image formed by the zoom lens into an electrical signal.

Images