KR101314329B1 - Zoom lens and photographing apparatus using the same - Google Patents

Abstract

A first lens group having overall negative refractive power, a second lens group having overall positive refractive power, and an aperture disposed between the first lens group and the second lens group in an order from the object side to the image side; And varying the distance between the first lens group and the second lens group, wherein the second lens group includes at least four lenses, and at least one lens surface of the lens positioned on the object side of the second lens group At least one lens surface of the aspherical surface and the lens located at the most image side is aspherical, and the object side lens surface of the lens located third from the object side is convex, and the lens located second from the object side is 65 <νd ₂₂ , R _22a / A zoom lens that satisfies the condition of R _22b < 0 and an imaging device having the same are provided.

Description

Zoom lens and photographing apparatus using the same}

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

An imaging optical system used in an imaging apparatus such as a conventional surveillance camera, a video camera, an electronic still camera, etc., comprising: a first lens group having negative refractive power and a second lens group having positive refractive power in order from an object side; BACKGROUND ART A two-group zoom lens is known in which shifting (zooming) is performed by moving two lens groups along an optical axis, and image variation correction and focusing according to this shift is performed by moving the first lens group.

Recently, surveillance cameras have been developed that can operate both day and night. Accordingly, the demand for zoom lenses for both visible and near-infrared rays suitable for surveillance cameras is increasing. In such a zoom lens for a surveillance camera, particularly, chromatic aberration is required to be maintained well. In addition, in order to cope with shooting in low light, a zoom lens that is bright at a large aperture ratio is required.

However, in the zoom lens designed for the visible region as in the prior art, chromatic aberration occurs especially in the near-infrared region, and thus there is a problem that the focus is not correct when shooting in the near-infrared region at night.

Japanese Patent Application Laid-Open No. 2002-244038 Japanese Patent Laid-Open No. 2004-264434 Japanese Patent Laid-Open No. 2006-133755 Japanese Patent Laid-Open No. 2008-052214

Embodiments of the present invention aim to provide a small large-diameter zoom lens capable of obtaining high optical performance from the visible region to the near infrared region and an imaging device having such a zoom lens.

According to an aspect of the present invention, in the order from the object side to the image side, the first lens group having a negative refractive power as a whole; A second lens group having an overall positive refractive power; And an aperture disposed between the first lens group and the second lens group.

Shifting by varying an interval between the first lens group and the second lens group, wherein the second lens group includes at least four lenses, and at least one of the lenses positioned on the object side of the second lens group The lens surface is an aspherical surface, and at least one lens surface of the lens located at the uppermost side is an aspherical surface, the object side lens surface of the lens located third from the object side is a convex surface, and the lens located second from the object side is as follows. Provide a zoom lens that satisfies the equation.

<Expression>

65 <νd ₂₂ , R _22a / R _22b <0

Here, νd ₂₂ represents the Abbe's number of the lens positioned second from the object side in the second lens group, R _22a represents the radius of curvature of the object-side lens surface, and R _22b represents the radius of curvature of the image-side lens surface.

According to one feature of the invention, the first lens group and the second lens group may satisfy the following equation.

<Expression>

1.0 <| f ₂ / f ₁ | <1.5

Here, f ₁ represents a composite focal length of the first lens group and f ₂ represents a composite focal length of the second lens group.

According to another feature of the invention, the following equation can be satisfied.

<Expression>

0.2 <f _w / f ₂ <0.4

Here, f _w represents the focal length of the electric field at the wide-angle end, and f ₂ represents the combined focal length of the second lens group.

According to another feature of the invention, the lens located on the most object side of the first lens group has a positive refractive power, it can satisfy the following equation.

<Expression>

25> νd ₁₃

Here, v d ₁₁ represents the Abbe's number of the lens located at the most upper side of the first lens group.

According to another feature of the invention, the second lens group may satisfy the following equation.

<Expression>

-1.5 <β _t2 <-1.0

Here, β _t2 represents the paraxial imaging magnification of the second lens group in the telephoto end.

According to another feature of the invention, the zoom lens can satisfy the following equation.

<Expression>

4.0 <Σ _d / f _t <6.5

Here,? _D represents the distance on the optical axis from the object-side vertex of the lens located on the most object side of the first lens group to the image plane, and f _t represents the focal length of the electric field at the telephoto end.

According to another feature of the present invention, the aperture stop does not move when the first lens group and the second lens group are shifted, and the zoom lens may satisfy the following equation.

<Expression>

0.8 <D _w / f ₂ <1.3

Here, Dw represents a distance from the aperture to the first principal point of the second lens group at a wide-angle end, and f ₂ represents a composite focal length of the second lens group.

According to still another aspect of the present invention, there is provided an image pickup device including the above-described zoom lens and a solid state image pickup element for picking up an image formed by the zoom lens.

According to the present invention as described above, it is possible to provide a small large-diameter zoom lens capable of obtaining high optical performance from the visible region to the near infrared region and an imaging device having such a zoom lens.

1 is a configuration diagram showing an example of a zoom lens according to an embodiment of the present invention.
2 is a configuration diagram of a zoom lens shown in Embodiment 1 of the present invention.
3 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the wide-angle end of the zoom lens shown in Example 1. FIG.
4 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the intermediate end of the zoom lens shown in Example 1. FIG.
5 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram in the telephoto end of the zoom lens shown in Example 1. FIG.
6 is a configuration diagram of a zoom lens shown in Embodiment 2 of the present invention.
7 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the wide-angle end of the zoom lens shown in Example 2. FIG.
FIG. 8 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the intermediate end of the zoom lens shown in Example 2. FIG.
9 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the telephoto end of the zoom lens shown in Example 2. FIG.
10 is a configuration diagram of a zoom lens shown in Embodiment 3 of the present invention.
11 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the wide-angle end of the zoom lens shown in Example 3. FIG.
12 shows spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, and magnification chromatic aberration diagrams at the intermediate stages of the zoom lens shown in Example 3. FIG.
FIG. 13 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the telephoto end of the zoom lens shown in Example 3. FIG.
14 is a configuration diagram of a zoom lens shown in Example 4 of the present invention.
FIG. 15 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the wide-angle end of the zoom lens shown in Example 4. FIG.
FIG. 16 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the intermediate stage of the zoom lens shown in Example 4. FIG.
17 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the telephoto end of the zoom lens shown in Example 4. FIG.
18 is a configuration diagram of a zoom lens shown in Example 5 of the present invention.
19 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the wide-angle end of the zoom lens shown in Example 5. FIG.
20 shows a spherical aberration diagram, astigmatism diagram, distortion aberration diagram, and magnification chromatic aberration diagram at the intermediate end of the zoom lens shown in Example 5. FIG.
21 shows spherical aberration, astigmatism, distortion, and magnification chromatic aberration at the telephoto end of the zoom lens shown in Example 5. FIG.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In addition, the lens data etc. which are illustrated by the following description are an example, Comprising: This invention is not necessarily limited to this, It can implement by changing suitably in the range which does not change the summary.

For example, as shown in FIG. 1, the zoom lens according to the embodiment of the present invention includes a first lens group L1 having negative refractive power as a whole and a second lens group L2 having a positive refractive power as a whole. Equipped. An aperture SP is disposed between the first lens group L1 and the second lens group L2, and an optical block G corresponding to an optical filter, a face plate, or the like is disposed between the second lens group L2 and the image plane IP.

In this zoom lens, the second lens group L2 is shifted along the optical axis in the direction of arrow a of FIG. 1 to perform zooming, and the first lens group L1 is moved along the optical axis in the arrow b, c directions of FIG. Correction and focusing are performed according to the variation. As a result, the effective length of the space between the first lens group L1 and the second lens group L2 can be achieved, thereby reducing the overall length of the zoom lens.

In addition, the arrow a shown by the solid line in FIG. 1 shows the movement locus (linear locus) of the 2nd lens group L2 when zooming from the wide-angle end to the telephoto end, and the arrow b and the dotted line which are shown by the solid line in FIG. The arrow c denoted by denotes a movement trajectory (trajectory protruding toward the upper surface IP) of the first lens group L1 for correcting the image surface variation due to the shift when focused on the infinity object and the near object, respectively.

1 illustrates three lenses 1 to 3 constituting the first lens group L1 and four lenses 4 to 7 constituting the second lens group L2 in order from the object side. The zoom lens according to the embodiment of the present invention is not necessarily limited to that of the present embodiment, and can be implemented by appropriately changing the scope of the present invention.

However, in order to obtain a small large-diameter zoom lens capable of obtaining high optical performance from the visible region to the near infrared region, it is necessary to appropriately correct spherical aberration and chromatic aberration, and also suppress the amount of aberration generated in the moving lens group due to miniaturization.

In order to solve such a problem, among the lens groups L1 and L2 constituting the zoom lens according to the embodiment of the present invention, the second lens group L2 is composed of at least four or more lenses 4-7, and the most At least one lens surface of the positioned lens 4 is an aspherical surface, and at least one lens surface of the lens 7 located on the uppermost surface side is an aspherical surface, and the object side lens surface of the lens 6 located third from the object side Let convex surface. As a result, the aberration at the lens periphery can be suppressed to correct the variation of the spherical aberration due to the variation.

In the zoom lens according to the embodiment of the present invention, the Abbe number of the lens 5 positioned second from the object side of the second lens group L2 is νd ₂₂ , and the radius of curvature of the object-side lens surface is R _22a [mm] and the image plane When the radius of curvature of the side lens surface is R _22b [mm], the relationship of the following formulas (1) and (2) is satisfied.

65 < v d ₂₂ . (One)

R _22a / R _22b <0... (2)

In the present invention, axial chromatic aberration can be corrected from the visible region to the near infrared region by satisfying the condition of the above formula (1). In addition, by satisfying the condition of Expression (2), axial chromatic aberration can be corrected in the near infrared region in the visible region while maintaining a positive refractive power.

In the zoom lens according to the embodiment of the present invention, when the composite focal length of the first lens group L1 is f1 [mm] and the composite focal length of the second lens group L2 is f ₂ [mm], the relationship of the following formula (3) It is desirable to satisfy.

1.0 <| f ₂ / f ₁ | <1.5... (3)

In the present invention, if the lower limit value of the above formula (3) is exceeded, the negative refractive power of the first lens group L1 is weakened, making the angle wider. In addition, the positive refractive power of the second lens group L2 becomes stronger, so that spherical aberration becomes excessively corrected, and large diameter hardening becomes difficult. On the other hand, if it deviates from the upper limit of said Formula (3), the positive refractive power of the 2nd lens group L2 will become weak, and the shift amount at the time of shifting from the wide angle end to the telephoto end state will increase, and the electric field will become long.

And in this invention, it is more preferable to satisfy | fill the relationship of following formula (3) '.

1.05 <| f ₂ / f ₁ | <1.3... (3) '

In the zoom lens according to the embodiment of the present invention, when the focal length of the electric field at the wide-angle end is f _w [mm], it is preferable to satisfy the relationship of the following formula (4).

0.2 <f _w / f ₂ <0.4... (4)

In the present invention, if it deviates from the lower limit of said Formula (4), spherical aberration will become excess correction, and coma aberration will become insufficient correction. On the other hand, if it deviates from the upper limit of said formula (4), spherical aberration and axial chromatic aberration will become lacking in correction, and coma aberration will become excess in correction.

And in this invention, it is more preferable to satisfy | fill the relationship of following formula (4) '.

0.25 <f _w / f ₂ <0.35... (4)'

In the zoom lens according to the embodiment of the present invention, when the lens 3 positioned on the uppermost side of the first lens group L1 has a positive refractive power, and the Abbe number of the lens 3 is νd ₁₃ , the following equation (5) It is desirable to satisfy the relationship

25> vd ₁₃ ... (5)

In the present invention, beyond the upper limit of the above formula (5), it becomes difficult to correct the axial chromatic aberration from the visible region to the near infrared region.

In the zoom lens according to the embodiment of the present invention, when the paraxial imaging magnification of the second lens group L2 in the telephoto end is β _t2 , it is preferable to satisfy the relationship of the following formula (6).

-1.5 <β _t2 <-1.0... (6)

In the present invention, beyond the lower limit of the above formula (6), it becomes difficult to correct the distortion aberration at the wide-angle end. On the other hand, if the deviation from the upper limit of the above formula (6), the amount of shift in shifting from the wide-angle end to the telephoto end state increases and the overall length becomes longer.

And in this invention, it is more preferable to satisfy | fill the relationship of following formula (6) '.

-1.3 < β _t2 < -1.1 (6) '

In the zoom lens according to the embodiment of the present invention, the distance on the optical axis from the object-side vertex of the lens 1 positioned on the most object side of the first lens group L1 to the image surface IP is Σ _d [mm], and the When the focal length is f _t [mm], it is preferable to satisfy the relationship of the following formula (7).

4.0 <Σ _d / f _t <6.5... (7)

In the present invention, the zoom lens can be miniaturized by exceeding the lower limit of the above formula (7), but it becomes difficult to correct the image curvature. On the other hand, if the upper limit of the equation (7) is exceeded, the aberration correction becomes easy, but the overall length of the zoom lens becomes long.

And in this invention, it is more preferable to satisfy | fill the relationship of following formula (7) '.

4.5 <Σ _d / f _t <6.0... (7) '

In the zoom lens according to the embodiment of the present invention, the aperture SP is arranged between the first lens group L1 and the second lens group L2 by fixing the distance to the upper surface IP so as not to move at the time of shifting, and the aperture SP at the wide angle end. When the distance from the first main point (object side main point) of the second lens group L2 to D _w [mm] and the combined focal length of the second lens group L2 are f ₂ [mm], the following equation (8) It is desirable to satisfy the relationship.

0.8 <D _w / f ₂ <1.3... (8)

In the present invention, if it is out of the lower limit of the above formula (8), the exit pupil distance cannot be sufficiently secured, and it cannot be perpendicularly incident on the upper surface IP. On the other hand, if it deviates from the upper limit of said Formula (8), the diameter of the 2nd lens group L2 will become large and the full length of a zoom lens will become long.

And in this invention, it is more preferable to satisfy | fill the relationship of following formula (8) '.

0.9 <D _w / f ₂ <1.2... (8)'

In the zoom lens according to the embodiment of the present invention, which satisfies the above conditions, all aberrations from the visible region to the near infrared region can be corrected well, thereby obtaining good optical performance from the wide-angle end to the telephoto end and at the same time shortening the overall length. By doing so, further miniaturization can be achieved.

The compact large-diameter zoom lens capable of obtaining such high optical performance can be used, for example, as an imaging optical system of an imaging device such as a surveillance camera, a digital video camera, or a digital still camera. In particular, when applied to a surveillance camera that can be operated both day and night, the chromatic aberration in the near-infrared region can be maintained well, and the spherical aberration variation due to the shift can be easily corrected. In order to cope with this, zoom lenses for both visible and near-infrared light can be realized at large ratios.

An imaging device having a zoom lens according to an embodiment of the present invention is a solid-state imaging device in which light incident on the object side of the zoom lens is finally disposed on an upper surface IP, for example, a CCD (Charge Coupled Device) or a CMOS (Complementary Mental-). The imaging surface of a solid-state imaging element (photoelectric conversion element) such as an oxide semiconductor device) sensor is formed. The solid-state image pickup device photoelectrically converts light received by the solid-state image pickup device to output it as an electric signal, and generates a digital image corresponding to the image of the subject, thereby producing a hard disk drive (HDD), a memory card, an optical disk, or a magnetic tape. It will record on the same recording medium. In addition, when the imaging device is a silver salt film camera, the upper surface IP corresponds to the film surface.

Hereinafter, the effect of this invention is made clear by an Example. In addition, this invention is not limited to a following example, It can change suitably and implement in the range which does not change the summary.

(Example 1)

The configuration of the zoom lens based on the design data of Embodiment 1 is shown in FIG. The zoom lens of the first embodiment shown in Fig. 2 has the same structure as the zoom lens shown in Fig. 1, and the design data of this zoom lens is as shown in Tables 1 to 4 below.

Face number (i) Lens (GjRk) R D  Nd  Vd One G1R1 18.671 0.850 1.83400 37.35 2 G1R2 7.780 6.090 3 G2R1 -49.352 0.800 1.77250 49.62 4 G2R2 9.514 1.100 5 G3R1 11.390 2.521 1.92286 20.88 6 G3R2 29.000 Variable 1 7 iris - Variable 2 8 G4R1 9.710 2.708 1.51633 64.07 9 G4R2 130.578 0.150 10 G5R1 8.829 4.453 1.49700 81.61 11 G5R2 -21.937 0.150 12 G6R1 15.801 1,000 1.92286 20.88 13 G6R2 4.952 0.350 14 G7R1 5.536 2.145 1.80860 40.42 15 G7R2 17.210 Variable 3 16 Plane 1.00E + 18 2.780 1.51680 64.20 17 Plane 1.00E + 18 3.399

Wide angle Middle Telephoto Focal length 2.82 4.90 9.68 F number 1.26 1.59 2.44 Variable 1 13.54 4.06 1.40 Variable 2  8.52 6.26 1.05 Variable 3 0.95 3.21 8.42

Conditional expression Example 1 (1) vd ₂₂ 81.61 (2) R _22a / R _22b -0.40 (3) | f ₂ / f ₁ | 1.08 (4) f _w / f ₂ 0.31 (5) vd ₁₃ 20.88 (6) β _t2 -1.14 (7) Σ _d / f _t 5.32 (8) D _w / f ₂ 0.99

Face number 8 9 15 C 0.10299 0.00766 0.05810 K 0 0 0 A ₄ -2.6651E-04 -2.2672E-05 5.3511E-04 A ₆ -5.0116E-06 -5.6152E-06 2.0734E-05 A ₈ 9.2186E-08 0.0000E + 00 4.8989E-07 A ₁₀ 0.0000E + 00 0.0000E + 00 0.0000E + 00

In addition, the surface number "i (i represents a natural number) shown in Table 1 is the number of the lens surface which sequentially increases as the lens surface of the lens located at the most object side among the lenses constituting the zoom lens is the first and goes to the image surface side. Indicates.

Further, in the lens "GjRk (j is a natural number, k is 1 or 2)" shown in Table 1, G denotes the lens positioned on the object side of the lenses constituting the zoom lens as the first lens and moves toward the image plane side. The numbers of the lenses are sequentially increased. On the other hand, R denotes the object side lens surface of each lens as 1 and the lens surface on the image surface side as 2. In addition, "aperture" and an "optical block (plane)" are also described in parallel.

In addition, "R" shown in Table 1 has shown the curvature radius [mm] of the lens surface corresponding to each surface number (however, the surface whose R value becomes ∞ is shown as the plane.).

In addition, "D" shown in Table 1 represents the axial spacing [mm] between the i th lens surface and the i + 1 th lens surface from the object side, and when it becomes variable, in Table 1 and Table 2, the wide-angle end is shown. , Axial plane spacing [mm] at the intermediate end and the telephoto end. In addition, "focal length" and "F number" at the wide end, the middle end, and the telephoto end are written in parallel.

In addition, "Nd" shown in Table 1 has shown the refractive index of each lens.

In addition, "v d" shown in Table 1 has shown the Abbe number of each lens.

In addition, in Table 3, (1) "νd ₂₂ ", (2) "R _22a / R _22b ", (3) "| f ₂ / f ₁ |", (4) "f _w / f ₂ ", ( 5) The conditional expressions of "νd ₁₁ ", (6) "β _t2 ", (7) "Σ _d / f _t ", and (8) "D _w / f ₂ " are shown.

In addition, Table 4 shows the surface numbers and the aspherical surface coefficients of the lens which became an aspherical surface. In addition, an aspherical surface can be represented by the following aspherical formula x.

3, 4, and 5 show spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, and magnification chromatic aberration diagrams of the zoom lens of the first embodiment configured as described above.

3 shows all aberration diagrams at the wide-angle end, FIG. 4 shows all aberration diagrams at the intermediate stage, and FIG. 5 shows all aberration diagrams at the telephoto end.

The spherical aberration diagram shows the spherical aberration in the d line (wavelength 57.56 nm) in solid line, and the spherical aberration in the near infrared region (wavelength 850 nm) in single-dot chain line.

The astigmatism diagram shows astigmatism with respect to sagittal light rays ΔS at each wavelength, and astigmatism with meridional light rays ΔM.

The distortion aberration diagram shows the distortion aberration (distortion) at the d line (wavelength 57.56 nm).

Magnification chromatic aberration shows chromatic aberration at g line (wavelength 435.84 nm).

The zoom lens of Example 1 satisfies the conditions of the present invention as shown in Tables 1 to 4. As for the zoom lens of the first embodiment, it can be seen that each aberration is well corrected as shown in Figs. 3, 4 and 5.

(Example 2)

The configuration of the zoom lens based on the design data of Example 2 is shown in FIG. In addition, the zoom lens of the second embodiment shown in FIG. 6 has the same configuration as the zoom lens shown in FIG. In addition, about the notation method of Tables 5-8, it is the same as that of Tables 1-4.

Face number (i) Lens (GjRk) R  D Nd Vd One G1R1 19.702 0.850 1.83400 37.35 2 G1R2 7.700 6.100 3 G2R1 -54.872 0.800 1.77250 49.62 4 G2R2 10.505 1.050 5 G3R1 12.002 2.436 1.92286 20.88 6 G3R2 30,000 Variable 1 7 iris - Variable 2 8 G4R1 9.000 2.577 1.51633 64.07 9 G4R2 43.369 0.150 10 G5R1 9.477 4.466 1.49700 81.61 11 G5R2 -15.822 0.150 12 G6R1 13.891 1,000 1.92286 20.88 13 G6R2 4.931 0.514 14 G7R1 5.648 2.151 1.80860 40.42 15 G7R2 15.006 Variable 3 16 Plane 1.00E + 18 2.780 1.51680 64.20 17 Plane 1.00E + 18 3.400

Wide angle Middle Telephoto Focal length 2.88 4.90 9.68 F number 1.26 1.52 2.43 Variable 1 13.68 4.30 1.30 Variable 2  8.35 6.18 1.03 Variable 3 1.04 3.21 8.36

Conditional expression Example 2 (1) vd ₂₂ 81.61 (2) R _22a / R _22b -0.60 (3) | f ₂ / f ₁ | 1.07 (4) f _w / f ₂ 0.31 (5) vd ₁₃ 20.88 (6) β _t2 -1.12 (7) Σ _d / f _t 5.32 (8) D _w / f ₂ 0.97

Face number 8 9 15 C 0.11111 0.02306 0.06664 K 0 0 0 A ₄ -3.8103E-04 -6.3247E-05 4.7327E-04 A ₆ -6.1883E-06 -5.9984E-06 2.6777E-05 A ₈ -1.4351E-07 0.0000E + 00 -1.2148E-07 A ₁₀ 0.0000E + 00 0.0000E + 00 0.0000E + 00

7, 8, and 9 show spherical aberration, astigmatism, distortion, and magnification chromatic aberration by the zoom lens of Example 2 configured as described above. In addition, the notation method of FIGS. 7 to 9 is the same as that of FIGS. 3 to 5.

The zoom lens of Example 2 satisfies the conditions of the present invention as shown in Tables 5 to 8. As for the zoom lens of the second embodiment, it can be seen that each aberration is well corrected as shown in FIGS. 7, 8, and 9.

(Example 3)

The configuration of the zoom lens based on the design data of Example 3 is shown in FIG. In addition, the zoom lens of Example 3 shown in FIG. 10 has the same structure as the zoom lens shown in FIG. 1, and the design data of the zoom lens shown in Example 3 is as shown in Tables 9 to 12 below. In addition, about the notation method of Table 9-12, it is the same as that of Table 1-4.

Face number (i) Lens (GjRk)  R D Nd Vd One G1R1 16.385 0.850 1.80420 46.50 2 G1R2 7.164 6.000 3 G2R1 -44.981 0.800 1.77250 49.62 4 G2R2 10.994 1.346 5 G3R1 12.561 2.313 1.92286 20.88 6 G3R2 28.612 Variable 1 7 iris - Variable 2 8 G4R1 8.524 2.175 1.51633 64.07 9 G4R2 17.989 0.150 10 G5R1 8.770 4.668 1.49700 81.61 11 G5R2 -12.787 0.150 12 G6R1 15.184 1,000 1.92286 20.88 13 G6R2 5.336 0.621 14 G7R1 5.456 2.298 1.80860 40.42 15 G7R2 12.914 Variable 3 16 Plane 1.00E + 18 2.780 1.51680 64.20 17 Plane 1.00E + 18 3.399

Wide angle Middle Telephoto Focal length 2.80 4.90 9.98 F number 1.27 1.57 2.54 Variable 1 14.11 4.20 1.40 Variable 2  7.87 5.62 0.15 Variable 3 0.97 3.22 8.69

Conditional expression Example 3 (1) vd ₂₂ 81.61 (2) R _22a / R _22b -0.69 (3) | f ₂ / f ₁ | 1.07 (4) f _w / f ₂ 0.30 (5) vd ₁₃ 20.88 (6) β _t2 -1.16 (7) Σ _d / f _t 5.16 (8) D _w / f ₂ 0.96

Face number 8 9 15 C 0.11731 0.05559 0.07743 K 0 0 0 A ₄ -2.9253E-04 1.2918E-04 7.8022E-04 A ₆ -3.1540E-06 -1.3051E-06 3.1728E-05 A ₈ -1.8741E-07 0.0000E + 00 1.0529E-06 A ₁₀ 0.0000E + 00 0.0000E + 00 0.0000E + 00

11, 12, and 13 show spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, and magnification chromatic aberration diagrams of the zoom lens of Example 3 configured as described above. In addition, the notation method of FIGS. 11 to 13 is the same as that of FIGS. 3 to 5.

The zoom lens of Example 3 satisfies the conditions of the present invention as shown in Tables 9-12. As for the zoom lens of the third embodiment, it can be seen that each aberration is well corrected as shown in Figs. 11, 12, and 13.

(Example 4)

The configuration of the zoom lens based on the design data of Example 4 is shown in FIG. In addition, the zoom lens of Example 4 shown in FIG. 14 has the same structure as the zoom lens shown in FIG. 1, and the design data of the zoom lens shown in Example 4 is as shown in Tables 13 to 16 below. In addition, the notation method of Tables 13-16 is the same as that of Tables 1-4.

Face number (i) Lens (GjRk) R D Nd Vd One G1R1 24.131 0.850 1.80610 33.27 2 G1R2 7.780 6.152 3 G2R1 -19.150 0.800 1.66672 48.30 4 G2R2 9.524 0.421 5 G3R1 10.926 3.027 1.92286 20.88 6 G3R2 57.067 Variable 1 7 iris - Variable 2 8 G4R1 7.706 2.768 1.51633 64.07 9 G4R2 28.854 0.150 10 G5R1 9.726 4.125 1.49700 81.61 11 G5R2 -18.169 0.150 12 G6R1 17.412 1,000 1.92286 20.88 13 G6R2 5.070 0.473 14 G7R1 5.828 2.581 1.80860 40.42 15 G7R2 25.968 Variable 3 16 Plane 1.00E + 18 2.780 1.51680 64.20 17 Plane 1.00E + 18 3.409

Wide angle Middle Telephoto Focal length 2.75 4.90 10.48 F number 1.24 1.50 2.59 Variable 1 13.73 3.31 0.65 Variable 2  8.88 6.57 0.55 Variable 3 0.70 3.01 9.03

Conditional expression Example 4 (1) vd ₂₂ 81.61 (2) R _22a / R _22b -0.54 (3) | f ₂ / f ₁ | 1.07 (4) f _w / f ₂ 0.30 (5) vd ₁₃ 20.88 (6) β _t2 -1.22 (7) Σ _d / f _t 4.96 (8) D _w / f ₂ 1.07

Face number 8 9 14 15 C 0.12978 0.03466 0.17159 0.03851 K 0 0 0 0 A ₄ -2.5907E-04 1.8515E-04 -4.2446E-05 3.0457E-04 A ₆ -3.8136E-06 -4.9586E-06 3.9881E-06 2.7436E-05 A ₈ -1.3436E-07 0.0000E + 00 -1.0308E-06 -1.9601E-06 A ₁₀ 0.0000E + 00 0.0000E + 00 0.0000E + 00 0.0000E + 00

15, 16, and 17 show spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, and magnification chromatic aberration diagrams of the zoom lens of the fourth embodiment configured as described above. In addition, the notation method of FIGS. 15 to 17 is the same as that of FIGS. 3 to 5.

The zoom lens of Example 4 satisfies the conditions of the present invention as shown in Tables 13 to 16. As for the zoom lens of the fourth embodiment, it can be seen that each aberration is well corrected as shown in Figs. 15, 16, and 17.

(Example 5)

The configuration of the zoom lens based on the design data of Example 5 is shown in FIG. In addition, the zoom lens of Example 5 shown in FIG. 18 is composed of the five lenses 4 to 8 of the second lens group L2, and the design data of the zoom lens shown in Example 5 is shown in Table 17 below. To Table 20. In addition, about the notation method of Table 17-20, it is the same as that of Table 1-4.

Face number (i) Lens (GjRk) R D  Nd  Vd One G1R1 18.081 0.850 1.83400 37.35 2 G1R2 7.780 6.100 3 G2R1 -71.036 0.800 1.7725 49.62 4 G2R2 9.342 1.100 5 G3R1 10.833 2.528 1.92286 20.88 6 G3R2 24.179 Variable 1 7 iris - Variable 2 8 G4R1 10.655 2.050 1.56330 64.07 9 G4R2 24.589 0.150 10 G5R1 10.668 4.397 1.49700 81.61 11 G5R2 -15.140 0.150 12 G6R1 40.061 1.929 1.80610 33.27 13 G6R2 -66.498 0.150 14 G7R1 25.050 1,000 1.92286 20.88 15      G7R2 5.414 0.155 16 G8R1 5.705E + 00 2.198 1.80860 40.42 17 GBR2 17.732E + 01 Variable 3 18 Plane 1.00E + 18 2.780 1.51680 64.20 19 Plane 1.00E + 18 3.399

Wide angle Middle Telephoto Focal length 2.88 4.90 9.68 F number 1.26 1.53 2.43 Variable 1 13.82 4.41 1.40 Variable 2  8.40 6.22 1.05 Variable 3 1.05 3.22 8.39

Conditional expression Example 5 (1) vd ₂₂ 81.61 (2) R _22a / R _22b -0.70 (3) | f ₂ / f ₁ | 1.08 (4) f _w / f ₂ 0.31 (5) vd ₁₃ 20.88 (6) β _t2 -1.12 (7) Σ _d / f _t 5.46 (8) D _w / f ₂ 1.00

Face number 8 9 15 C 0.09385 0.04067 0.05639 K 0 0 0 A ₄ -3.3433E-04 3.6086E-05 3.6550E-04 A ₆ -5.2936E-06 -4.4521E-06 2.0757E-05 A ₈ -8.4144E-08 0.0000E + 00 9.4427E-08 A ₁₀ 0.0000E + 00 0.0000E + 00 0.0000E + 00

19, 20, and 21 show spherical aberration diagrams, astigmatism diagrams, distortion aberration diagrams, and magnification chromatic aberration diagrams of the zoom lens of the fifth embodiment configured as described above. In addition, the notation method of FIGS. 19 to 21 is the same as that of FIGS. 3 to 5.

The zoom lens of Example 5 satisfies the conditions of the present invention as shown in Tables 17 to 20. As for the zoom lens of the fifth embodiment, it can be seen that each aberration is well corrected, as shown in FIGS. 19, 20, and 21.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such modifications and variations as fall within the true spirit of the invention.

L1: first lens group
L2: second lens group
1 to 3: lens constituting the first lens group
4 to 7: lenses constituting the second lens group
SP: Aperture
G: optical block
IP: Top

Claims (8)

In order from the object side to the upper side,
A first lens group having overall negative refractive power;
A second lens group having an overall positive refractive power; And
And an aperture disposed between the first lens group and the second lens group.
Changing the interval between the first lens group and the second lens group to perform shifting,
The second lens group includes at least four lenses, and at least one lens surface of the lens positioned at the object side of the second lens group is an aspherical surface, and at least one lens positioned at the most image side of the second lens group. The lens surface is an aspherical surface, the object-side lens surface of the lens located third from the object side of the second lens group is a convex surface, and the lens located second from the object side of the second lens group satisfies the following equation. Zoom lens.
<Expression>
65 <νd ₂₂
R _22a / R _22b <0
4.0 <Σ _d / f _t <6.5

Here, νd ₂₂ represents the Abbe's number of the lens positioned second from the object side in the second lens group, R _22a represents the radius of curvature of the object-side lens surface, and R _22b represents the radius of curvature of the image-side lens surface. Σ _d represents the distance on the optical axis from the object-side vertex of the lens located on the object side of the first lens group to the image plane, and f _t represents the focal length of the electric field at the telephoto end. The method of claim 1,
The zoom lens of the first lens group and the second lens group satisfy the following equation.
<Expression>
1.0 <| f ₂ / f ₁ | <1.5
Here, f ₁ represents a composite focal length of the first lens group and f ₂ represents a composite focal length of the second lens group. The method of claim 1,
Zoom lens satisfying the following equation.
<Expression>
0.2 <f _w / f ₂ <0.4
Here, f _w represents the focal length of the electric field at the wide-angle end, and f ₂ represents the combined focal length of the second lens group. The method of claim 1,
The lens located at the top of the first lens group has a positive refractive power, the zoom lens satisfying the following equation.
<Expression>
25> νd ₁₃
Here, νd ₁₃ represents the Abbe's number of the lens located at the most image side of the first lens group. The method of claim 1,
The second lens group is a zoom lens that satisfies the following equation.
<Expression>
-1.5 <β _t2 <-1.0
Here, β _t2 represents the paraxial imaging magnification of the second lens group in the telephoto end. delete The method of claim 1,
The iris does not move when the first lens group and the second lens group are shifted.
The zoom lens is a zoom lens satisfying the following equation.
<Expression>
0.8 <D _w / f ₂ <1.3
Here, Dw represents a distance from the aperture to the first principal point of the second lens group at a wide-angle end, and f ₂ represents a composite focal length of the second lens group. The zoom lens according to claim 1,
An imaging device comprising a solid-state imaging device for imaging an image formed by the zoom lens.

Images