JPWO2012090757A1 - Zoom lens and imaging device - Google Patents

Abstract

Provided are a compact, thin, wide-angle, high-magnification zoom lens capable of correcting camera shake and ensuring good optical performance, and an imaging device equipped with the zoom lens. If the value of conditional expression (1) is below the lower limit, the amount of lens shift required to shift the image by a certain predetermined amount becomes too small, and high accuracy is required for control of the driving device. Will be expensive. On the other hand, if the value of the conditional expression (1) exceeds the upper limit, the lens shift amount necessary for shifting the image by a certain predetermined amount becomes too large, and the shift direction is the same as the incident optical axis direction. An increase in the thickness hinders thinning. Therefore, it is preferable to satisfy the range of conditional expression (1). 0.2 <fs / ft <0.9 (1) The focal length of the shift lens that is the second lens from the object side of the fifth lens group is fs (mm), and the focal length of the telephoto end of the entire system is ft ( mm).

Description

  The present invention is suitable for photographing optical systems of digital input / output devices such as digital still cameras and digital video cameras, has a high zoom ratio and has a camera shake correction function, and is excellent in miniaturization, thinning, and wide-angle. The present invention relates to a lens and an imaging apparatus using the lens.

  In recent years, imaging devices using solid-state imaging devices such as digital still cameras have been widely used, and further higher image quality has been demanded. Especially in digital still cameras having a large number of pixels, the number of pixels There is a need for a photographic lens with excellent imaging performance that is compatible with many solid-state imaging devices, particularly a zoom lens that is small, thin, wide-angle, and highly variable.

  On the other hand, as a result of promoting the thinning of the imaging device, image blurring during shooting is likely to occur. In addition to this, image blurring during shooting is further conspicuous due to the increase in the number of pixels of the imaging element and the increase in magnification. In order to cope with the situation that it becomes easy, a zoom lens to which a camera shake correction function is added is required.

  Here, in the zoom lens described in Patent Document 1, the first lens group located closest to the object side has a reflecting member for bending the optical axis by 90 degrees, thereby reducing the size and thickness of the incident optical axis. In the figure, the final lens closest to the image side of the final lens group positioned closest to the image side is shifted in a direction perpendicular to the optical axis to correct image blur of the zoom lens.

  In the zoom lens described in Patent Document 2, the first lens group located closest to the object side has a reflecting member for bending the optical axis by 90 degrees, thereby reducing the size and thickness of the incident optical axis. In this figure, the second lens from the image side of the last lens group located closest to the image side is shifted in a direction perpendicular to the optical axis to correct the image blur of the zoom lens.

JP 2007-328306 JP JP 2009-192771

  However, in the zoom lens described in Patent Document 1, the image blur of the zoom lens is corrected by shifting the final lens closest to the image side of the final lens group positioned closest to the image side in a direction perpendicular to the optical axis. However, since the image sensor is close, the back focus must be increased to avoid interference with the image sensor and to secure the drive mechanism space, resulting in an increase in the overall optical length. Therefore, it is not possible to reduce the size sufficiently.

  On the other hand, in the zoom lens described in Patent Document 2, the second lens from the image side of the last lens group located closest to the image side is shifted in a direction perpendicular to the optical axis, and the image blur of the zoom lens is reduced. Although corrected, the zoom lens has not achieved sufficiently high zooming and widening.

  In view of the above-described problems, the present invention provides a compact, thin, wide-angle, high-magnification zoom lens capable of correcting camera shake and ensuring good optical performance, and an imaging device equipped with the zoom lens. With the goal.

The zoom lens according to claim 1,
From the object side,
A first lens unit having a positive refractive power that is fixed at the time of zooming;
A second lens group having a negative refractive power that moves along the optical axis at the time of zooming;
A third lens group having a positive refractive power which is fixed at the time of zooming;
A fourth lens group having a positive refractive power that moves along the optical axis upon zooming;
Consists of a fifth lens group fixed at the time of zooming,
The first lens group has a reflecting member for bending the optical axis,
The fourth lens group is composed of a cemented lens in which a negative lens and a positive lens are bonded together in order from the object side,
The fifth lens group includes a first negative lens having negative refractive power, a second positive lens having positive refractive power, and a third lens in order from the object side.
The second positive lens of the fifth lens group is shifted in a direction perpendicular to the optical axis to correct image blur, and the focal length of the second positive lens of the fifth lens group is fs (mm). The following conditional expression is satisfied, where the focal length at the telephoto end is ft (mm).
0.2 <fs / ft <0.9 (1)

  According to the present invention, the second lens group and the fourth lens group constitute a zooming system, and in addition to the second lens group, the fourth lens group also has a zooming function, so that the second lens group and the fourth lens group have a zooming function. The moving distance due to the zooming of the lens group can be reduced, and the distance from the aperture stop to the first lens closest to the object side of the first lens group can be reduced, and as a result, it passes through the first lens. Since the distance from the optical axis of the off-axis light beam is reduced, the effective diameter of the first lens can be reduced, and the zoom lens can be reduced in size. Further, by using two lens groups that move by zooming or focusing, it is possible to reduce the number of driving devices and to achieve a reduction in size and thickness.

  Further, the first lens group has a reflecting member for bending the optical axis, and this reduces the size in the direction of the incident optical axis, so that the size in the thickness direction of the imaging device can be reduced.

  Further, the fourth lens group is composed of a cemented lens in which a negative lens and a positive lens are bonded in order from the object side, whereby astigmatism can be favorably corrected to ensure high optical performance.

  Conditional expression (1) is a conditional expression that defines the ratio of the focal length of the second positive lens of the fifth lens group that shifts during camera shake correction to the telephoto end of the entire system. If the value of conditional expression (1) is below the lower limit, that is, the power of the shift lens becomes too strong, the amount of lens shift required to shift the image by a certain predetermined amount becomes too small, and the drive device is controlled. High accuracy is required, and the imaging device becomes expensive. On the other hand, if the value of the conditional expression (1) exceeds the upper limit, that is, the power of the shift lens becomes too weak, the amount of lens shift necessary to shift the image by a certain predetermined amount becomes too large, and the shift direction is changed. Since it is the same as the direction of the incident optical axis, an increase in the shift amount hinders thinning. Therefore, it is preferable to satisfy the range of conditional expression (1).

  Further, by shifting the second positive lens of the fixed fifth lens group at the time of zooming or focusing, it is possible to eliminate the interference between the camera shake correction drive mechanism and other drive mechanisms, thereby further reducing the size. be able to. Furthermore, by using the shift lens as the positive lens, the chromatic aberration of magnification can be suppressed, so that high optical performance can be ensured.

A zoom lens according to a second aspect of the present invention is the zoom lens according to the first aspect, wherein the distance that the second lens group moves by zooming from the wide-angle end to the telephoto end is d2 (mm), and the fourth lens group is It is characterized in that the following conditional expression is satisfied, where d4 (mm) is the distance moved by zooming from the wide-angle end to the telephoto end.
0.4 <d2 / d4 <0.9 (2)

  The conditional expression (2) is a conditional expression that defines the ratio of the moving amounts of the second lens group and the fourth lens group that move during zooming. When the value of conditional expression (2) is below the lower limit, that is, as a result of the movement amount of the second lens group being too small compared to the movement amount of the fourth lens group, the zooming effect in the second lens group is reduced. If the fourth lens group is provided with the zooming effect corresponding to that amount, the effective diameter after the fourth lens group increases, and the thinning of the imaging device is hindered. Further, if the zooming effect in the second lens group is to be maintained, there is a risk that the power of the second lens group becomes strong, making it difficult to ensure optical performance, and the error sensitivity increases. On the other hand, if the value of conditional expression (2) exceeds the upper limit, that is, the amount of movement of the second lens group becomes too large compared to the amount of movement of the fourth lens group, the object side of the first lens group from the aperture stop is the most object side. In this case, the distance to the first lens increases, and it is necessary to increase the effective diameter of the first lens. As a result, there is a possibility that miniaturization and thinning may be hindered. Therefore, it is preferable to satisfy the conditional expression (2).

  A zoom lens according to a third aspect of the present invention is the zoom lens according to the first or second aspect, wherein the second lens group includes three or less lenses.

  As a result, the amount of movement during zooming can be earned without increasing the total optical length, and even higher zooming can be realized, or when the zooming ratio is kept equal, Power can be weakened, various aberrations can be suppressed, and error sensitivity can be reduced. In addition to reducing the number of lenses, the cost can be reduced and the load on the lens driving actuator can be reduced.

A zoom lens according to a fourth aspect is the invention according to any one of the first to third aspects, wherein a lateral magnification of the second positive lens of the fifth lens group is βs, and the third magnification of the fifth lens group is the third. The following conditional expression is satisfied, where βp is the lateral magnification of the lens.
0.5 <(1-βs) × βp <1.6 (3)

  The conditional expression (3) is a conditional expression that defines the ratio of how much the image is shifted with respect to the unit movement amount of the second positive lens of the fifth lens group that is shifted during camera shake correction. If the value of conditional expression (3) is below the lower limit, that is, the amount of lens shift required to shift the image by a certain predetermined amount increases, and the shift direction is the same as the incident optical axis direction, thereby preventing thinning. There is a risk of becoming. On the other hand, if the value of the conditional expression (3) exceeds the upper limit, that is, the lens shift amount required to shift the image by a certain predetermined amount becomes small, and high accuracy is required for the control of the driving device, and the imaging device May become expensive. Therefore, it is preferable to satisfy the conditional expression (3).

  According to a fifth aspect of the present invention, in the zoom lens according to any one of the first to fourth aspects, the third lens of the fifth lens group is made of plastic.

  As a result, it becomes easy to add an aspherical shape to the third lens, and therefore various aberration corrections can be performed to ensure high optical performance. Furthermore, since plastic is cheaper and lighter than glass, it contributes to cost reduction and weight reduction.

The zoom lens according to claim 6 satisfies the following conditional expression in the invention according to any one of claims 1 to 5, wherein the focal length of the third lens of the fifth lens group is fp (mm). It is characterized by doing.
0.3 <| fp / ft | (4)

  Conditional expression (4) is a conditional expression that defines the ratio of the focal lengths of the third lens and the telephoto end of the entire system. If the value of conditional expression (4) is lower than the lower limit, that is, if the power of the third lens becomes too strong, the influence of the refractive index change due to the temperature change of the plastic becomes large, and the focus shift and the optical performance are greatly deteriorated. There is a risk of becoming. Therefore, it is preferable to satisfy the conditional expression (4).

A zoom lens according to a seventh aspect is the invention according to any one of the first to sixth aspects, wherein the focal length at the wide angle end of the entire system is fw (mm), and the object side of the first lens of the first lens group is The following conditional expression is satisfied, where d _L1PR (mm) is a distance on the optical axis from the apex to the reflecting surface of the reflecting member.
1.0 < _dL1PR / fw <1.6 (5)

  The conditional expression (5) is a conditional expression showing the relationship between the magnitude in the incident optical axis direction and the zoom ratio. If the value of conditional expression (5) is below the lower limit, various aberrations cannot be corrected well, and optical performance may not be ensured. On the other hand, if the value of the conditional expression (5) exceeds the upper limit, there is a possibility that miniaturization and high zooming cannot be performed. Therefore, it is preferable to satisfy the conditional expression (5).

  A zoom lens according to an eighth aspect of the present invention is the zoom lens according to any one of the first to seventh aspects, wherein the aperture stop is between the third lens group and the fourth lens group.

  Accordingly, it is possible to avoid the second lens group from interfering with the aperture stop member, so that it is possible to obtain a moving distance by zooming and to realize further high zooming.

A zoom lens according to a ninth aspect is the zoom lens according to any one of the first to eighth aspects, wherein the subject image is formed on an imaging surface of the solid-state imaging device having a diagonal length of 2Y ′ (mm). The lens is characterized in that the following conditional expression is satisfied, where the focal length at the wide-angle end of the entire system is fw (mm).
1.3 <2Y ′ / fw <1.8 (6)

  The conditional expression (6) is a conditional expression that defines the ratio between the size of the solid-state imaging device and the wide-angle end focal length. If the value of conditional expression (6) is below the lower limit, there is a risk that sufficient widening cannot be realized. On the other hand, if the value of conditional expression (6) exceeds the upper limit, the off-axis aberration becomes too large, and there is a possibility that good optical performance cannot be ensured. Therefore, it is preferable to satisfy the conditional expression (6).

  A zoom lens according to a tenth aspect is the invention according to any one of the first to ninth aspects, further comprising a lens group having substantially no refractive power. That is, even when a dummy lens having substantially no refractive power is added to the configurations of claims 1 to 9, it is within the scope of the present invention.

  An image pickup apparatus according to an eleventh aspect includes the zoom lens according to any one of the first to tenth aspects.

  According to the present invention, it is possible to provide a compact, thin, wide-angle high-magnification zoom lens capable of correcting camera shake and ensuring good optical performance, and an imaging device equipped with the zoom lens.

It is a front side perspective view of imaging device 10 of this embodiment. It is a back side perspective view of imaging device 10 of this embodiment. It is the figure which cut | disconnected the structure of FIG. 1 by the surface containing a III-III line | wire, and looked at the arrow direction. 2 is a cross-sectional view of an imaging lens of Example 1. FIG. FIG. 4 is an aberration diagram at the wide-angle end of Example 1. FIG. 6 is an aberration diagram at the intermediate end of Example 1. FIG. 3 is an aberration diagram at the telephoto end of Example 1. 6 is a cross-sectional view of an imaging lens of Example 2. FIG. FIG. 6 is an aberration diagram at the wide-angle end of Example 2. FIG. 6 is an aberration diagram at the intermediate end of Example 2. FIG. 6 is an aberration diagram at the telephoto end of Example 2. 6 is a cross-sectional view of an imaging lens of Example 3. FIG. FIG. 6 is an aberration diagram at the wide-angle end of Example 3. FIG. 6 is an aberration diagram at the intermediate end of Example 3. FIG. 7 is an aberration diagram at the telephoto end of Example 3. 6 is a cross-sectional view of an imaging lens of Example 4. FIG. FIG. 6 is an aberration diagram at the wide-angle end of Example 4. FIG. 6 is an aberration diagram at the intermediate end of Example 4. FIG. 6 is an aberration diagram at the telephoto end of Example 4. 6 is a cross-sectional view of an imaging lens of Example 5. FIG. FIG. 10 is an aberration diagram at the wide-angle end of Example 5. FIG. 6 is an aberration diagram at the intermediate end of Example 5. FIG. 6 is an aberration diagram at the telephoto end of Example 5. 6 is a cross-sectional view of an imaging lens of Example 6. FIG. FIG. 10 is an aberration diagram at the wide angle end according to Example 6. FIG. 10 is an aberration diagram at the intermediate end of Example 6. FIG. 6 is an aberration diagram at the telephoto end of Example 6.

  An imaging apparatus according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front perspective view of the imaging apparatus 10 of the present embodiment, and FIG. 2 is a rear perspective view of the imaging apparatus 10 of the present embodiment.

  An imaging apparatus 10 that is a digital still camera has a housing 12 that forms an exterior. As shown in FIGS. 1 and 2, the housing 12 is a flat, thin rectangle having a thickness in the front-rear direction, a height in the vertical direction larger than the thickness, and a width in the left-right direction larger than the height. It is formed in a plate shape.

  As shown in FIG. 1, an opening 12a is provided at a location near the right side of the front upper portion of the housing 12, and a first lens group of an imaging lens system, which will be described later, is provided facing the front through the opening 12a. ing. A cover member 14 capable of shielding the opening 12a is provided on the front surface.

  As shown in FIG. 2, on the back surface of the housing 12, a captured image (image data) is displayed, and a display 32 that displays an operation screen or a menu screen for performing various setting operations related to imaging and reproduction. Is provided. A display unit is constituted by the display 32. As the display 32, a conventionally known display device such as a liquid crystal display device or an organic EL display device can be adopted.

  A release button 34 and a power switch 36 are provided on the top surface of the housing 12. On the left side of the rear surface of the housing 12, a zoom operation switch 38 for adjusting the zoom ratio of the imaging lens system to the telephoto side (tele side) or the wide angle side (wide side), and switching of the imaging mode and playback mode, etc. A plurality of operation switches 40 are provided for performing various operations, a selection operation of a selection item on a menu screen displayed on the display 32, a setting item setting operation, and the like.

  FIG. 3 is a diagram of the configuration of FIG. 1 cut along a plane including a line III-III and viewed in the direction of the arrow. The protective plate 42 attached to the housing 12 of FIG. 1 is configured such that a rectangular plate-like display 32 is bonded to the front side with a double-sided tape or the like (snap fit may be used), and a lens barrel 50 is attached to the back side. .

A bending zoom lens ZL is accommodated in a rectangular parallelepiped lens barrel 50. The zoom lens ZL includes a first lens group GR1 having a fixed positive refractive power at the time of zooming, a second lens group GR2 having a negative refractive power that moves by being lead to the optical axis at the time of zooming, and is fixed at the time of zooming. A first lens group GR3 having a positive refractive power, a fourth lens group GR4 having a positive refractive power that moves by lead on the optical axis at the time of zooming, and a fifth lens group GR5 fixed at the time of zooming, The lens group GR1 has a reflecting member MR for bending the optical axis, the fourth lens group GR4 is constituted by a cemented lens in which a negative lens G7 and a positive lens G8 are bonded in order from the object side, and a fifth lens group GR5 is formed. The lens is composed of a negative lens G9, a positive lens G10, and a lens G11 in order from the object side. The positive lens G10 of the fifth lens group GR5 is shifted in a direction perpendicular to the optical axis to correct image blur, and the fifth lens group GR5 Focus of positive lens G10 A release fs (mm), the focal length at the telephoto end of the entire system as ft (mm), satisfy the following equation.
0.2 <fs / ft <0.9 (1)

  Next, the configuration of each lens group will be described in detail. The first lens group GR1 includes a first lens G1, a reflective member MR, and a second lens G2 in order from the object side. The first lens G1 located closest to the object side is a negative meniscus lens having a convex shape directed toward the object side. Thereby, it is possible to reduce the incident angle of the light beam incident on the first surface of the first lens G1 and suppress the occurrence of various aberrations. In addition, the angle formed by the off-axis ray incident on the first surface of the reflecting member MR that is in contact with the image side and the optical axis can be reduced, and the diameter of the reflecting member MR can be reduced. Since the size of the reflecting member MR is a major factor that determines the size in the direction of the incident optical axis, it can be said that downsizing the reflecting member MR as much as possible is indispensable for realizing a reduction in thickness. However, if the negative refractive power is too strong, it is necessary to increase the power of the second lens G2 adjacent to the image side of the reflecting member MR in order to make the first lens group GR1 have a positive refractive power. As a result, the power of both the first lens G1 and the second lens G2 becomes strong, and various aberrations are likely to occur. In addition, since the first lens group GR1 is fixed at the time of zooming, the zoom lens approaches the subject at the time of photographing and does not give a sense of pressure to the subject. Even if the camera or the zoom lens receives an impact from the outside, the zoom lens does not protrude greatly, so there is little adverse effect of the impact.

  Further, by using a glass material having a high refractive index for the reflecting member MR, the reflecting member MR can be further reduced in size. The second lens G2 has a positive refractive power so as to make the first lens group GR1 have a positive power, and is a biconvex lens. The second lens G2 is a molded lens to which an aspherical shape is added. As a result of reducing the size of the reflecting member MR by increasing the negative power of the first lens G1 to some extent, the role of correcting various aberrations generated thereby. Is responsible.

  The second lens group GR2 includes a third lens G3, a fourth lens G4, and a fifth lens G5 in order from the object side. The fourth lens G4 and the fifth lens G5 are cemented to form a cemented lens. The second lens group GR2 has a negative refractive power. This is because the position of the entrance pupil is brought closer to the first lens group GR1, and thereby the position of the entrance pupil of the entire lens system is brought closer to the object side. In addition, the reflecting member MR of the first lens group GR1 can be reduced in size and reduced in thickness, and aberration variation at the time of zooming can be suppressed. It is valid.

  The third lens G3 and the fourth lens G4 are biconcave lenses waiting for negative power, and the negative power of the second lens group GR2 is dispersed to suppress various aberrations. In particular, since the second lens group GR2 moves during zooming, it is possible to suppress aberration fluctuations during zooming by dispersing the group power to each lens. The fifth lens G5 is a positive meniscus lens having a convex shape directed toward the object side, and plays a role of correcting various aberrations. The fourth lens G4 having a negative power and the fifth lens G5 having a positive power are cemented and have an effect of correcting chromatic aberration.

  The third lens group GR3 includes only the sixth lens G6. The sixth lens is a biconvex lens having a positive refractive power, and is a molded lens to which an aspherical shape is added. Since the lens near the aperture stop has a great influence on the spherical aberration, the effect of correcting the spherical aberration can be enhanced by adding an aspherical shape. The shutter mechanism 60 has a plurality of aperture blades S around the opening 60a, and has an aperture stop function of opening and closing the aperture blades S to restrict the aperture 60a when energized from the outside. Since the third lens group GR3 is fixed at the time of zooming, it is possible to prevent the diaphragm mechanism from becoming complicated by providing the fixed third lens group GR3 with a diaphragm mechanism.

  The fourth lens group GR4 is configured by a seventh lens G7 and an eighth lens G8 in order from the object side, and the seventh lens G7 and the eighth lens G8 are cemented to form a cemented lens. The seventh lens G7 is a negative meniscus lens having a convex shape facing the object side, and the eighth lens G8 is a biconvex lens. Astigmatism can be corrected better than the case of positive and negative by making the joining order negative and positive from the object side.

  The fifth lens group GR5 includes a ninth lens G9, a tenth lens G10, and an eleventh lens G11 in order from the object side. The ninth lens G9 is a negative meniscus lens having a convex shape directed toward the object side, and is expected to have an effect of correcting the curvature of field and astigmatism by reducing the Petzval sum. The tenth lens G10 is a biconvex lens and is also a shift lens during camera shake correction. By increasing this power, it is possible to achieve a sufficient camera shake correction effect and to have a function to contribute to aberration correction by reducing the power of the eleventh lens G11 adjacent to the image side. The eleventh lens G11 is a biconcave lens in the paraxial region, and is formed of a plastic that can be easily added with an aspherical shape. For example, the eleventh lens G11 has an effect of correcting distortion aberration that tends to increase when the angle is widened. . Although the fifth lens group GR5 is fixed at the time of zooming, since the camera shake correction mechanism is disposed in the fixed fifth lens group GR5, it is possible to prevent the camera shake correction mechanism from becoming complicated. Further, by fixing the fifth lens group GR5 closest to the solid-state image sensor IM, dust can be prevented from entering the solid-state image sensor IM.

  A low-pass filter LP and a cover glass CG are provided between the fifth lens group GR5 and the solid-state imaging device IM provided at the rear end of the lens frame 50.

  The operation of the imaging device in this embodiment will be described. 1 and 2, by operating the zoom operation switch 38 with the power switch 36 turned on, the second lens group GR2 and the fourth lens group GR4 move in the optical axis direction in a predetermined relationship. Therefore, the zooming is realized. Further, the fourth lens group GR4 is moved in the optical axis direction by a known image plane AF function to achieve focusing.

  Further, when the release button 34 is depressed, the subject light incident through the imaging lens system enters the imaging surface of the imaging element IM for a predetermined exposure time defined by the shutter mechanism 60 and is converted into an image signal. After performing predetermined image processing, a subject image based on the image signal is displayed on the display 32. At this time, a camera shake correction mechanism (not shown) moves the tenth lens G10 in the direction orthogonal to the optical axis in accordance with the camera shake of the imaging device 10, thereby realizing camera shake correction.

Examples of the imaging lens of the present invention are shown below. Symbols used in each example are as follows.
s: surface number
Fno: F number Y: Maximum real image height Y ': Half the diagonal length of the imaging surface of the solid-state image sensor (maximum ideal image height)
ω: Half angle of view (°)
r: radius of curvature dx: spacing between the upper surface of the x-th surface and the (x + 1) -th surface
nd: Refractive index of lens material with respect to d-line νd: Abbe number with respect to d-line of lens material The aspherical shape has the apex of the surface as the origin, the X axis in the optical axis direction, and the direction perpendicular to the optical axis. The height is represented by the following formula 1, where h.

但し、
Ａｉ：ｉ次の非球面係数
Ｒ（レンズデータ表ではｒ）：曲率半径
Ｋ：円錐定数
また、非球面係数において、１０のべき乗数（例えば２．５×１０^-02）をＥ（例えば２．５Ｅ−０２）を用いて表している。

However,
Ai: i-th order aspheric coefficient R (r in the lens data table): radius of curvature K: conic constant Further, in the aspheric coefficient, a power of 10 (for example, 2.5 × 10 ⁻⁰² ) is changed to E (for example, 2. 5E-02).

Example 1
Table 1 shows lens data of Example 1. FIG. 4 is a cross-sectional view of the imaging lens of Example 1, and schematically shows the movement of the lens during zooming with an arrow. The reference numerals shown in FIG. 4 correspond to the reference numerals of the components in the embodiment of FIG. FIG. 5 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion aberration (c)) at the wide-angle end in Example 1. FIG. 6 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end of the first embodiment. FIG. 7 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 1. In each spherical aberration diagram, the solid line indicates the spherical aberration at the d line, and the dotted line indicates the spherical aberration at the g line. In each astigmatism diagram, a solid line S represents a sagittal surface, and a dotted line M represents a meridional surface (the same applies hereinafter).

[Table 1] Numerical Example 1
Optical system data
sr (mm) d (mm) nd νd
1 85.0612 0.500 1.92286 20.9
2 13.0935 1.425
3 infinity 8.650 1.84666 23.8
4 infinity 0.500
5 11.7793 2.595 1.75501 51.2
6 -20.4054 variable
7 -110.9948 0.500 1.88300 40.8
8 7.0820 0.824
9 -9.3559 0.500 1.83481 42.7
10 7.4220 0.884 1.94595 18.0
11 54.2473 variable
12 12.7312 1.051 1.55332 71.7
13 -13.3610 0.700
14 infinity variable Aperture stop
15 13.5460 0.521 1.92286 20.9
16 7.1451 2.843 1.65844 50.9
17 -19.7071 variable
18 197.8515 0.500 1.90366 31.3
19 13.4476 0.400
20 7.7853 2.800 1.49700 81.6
21 -17.7201 1.714
22 -15.1077 2.077 1.54470 56.2
23 29.4674 0.885
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 1.686

Each value at the wide-angle end, intermediate position, and telephoto end Focal length (mm) 5.06 10.92 24.02
Fno 3.90 4.32 5.43
ω (degrees) 37.68 19.68 9.24
d6 (mm) 0.460 4.575 7.352
d11 (mm) 7.292 3.178 0.400
d14 (mm) 11.379 6.424 2.010
d17 (mm) 1.813 6.768 11.182

Aspheric coefficient Ai and conic constant K of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -6.20156E-05 2.07328E-07 -2.17580E-08 0 0
6 0 1.16263E-04 -5.12927E-07 -8.38393E-09 0 0
12 0 -8.72840E-05 7.07976E-05 -2.07468E-05 1.70017E-06 0
13 0 1.01245E-04 1.24763E-04 -2.71962E-05 1.82827E-06 0
22 0 -3.92863E-03 -3.28484E-05 8.86024E-06 -2.66184E-07 1.39359E-17
23 0 -5.25970E-03 7.92006E-05 2.76163E-06 -1.07715E-07 1.62171E-12

Other specifications Total lens length (mm) 54.000
Back focus (mm) 3.731
First lens group focal length (mm) 12.584
Second lens group focal length (mm) -4.225
Third lens group focal length (mm) 11.954
Fourth lens group focal length (mm) 15.930
5th lens group focal length (mm) -46.889
Zoom ratio 4.747
Y '(mm) 3.906

(Example 2)
Table 2 shows lens data of Example 2. FIG. 8 is a cross-sectional view of the image pickup lens of Example 2. The movement of the lens at the time of zooming is schematically shown by arrows. The reference numerals shown in FIG. 8 correspond to the reference numerals of the components in the embodiment of FIG. FIG. 9 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion aberration (c)) at the wide-angle end in Example 2. FIG. 10 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end of the second embodiment. FIG. 11 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 2.

[Table 2] Numerical Example 2
Optical system data
sr (mm) d (mm) nd νd
1 114.2441 0.500 1.92286 20.9
2 11.5860 1.548
3 infinity 8.405 1.84666 23.8
4 infinity 0.683
5 10.9514 2.597 1.72903 54.0
6 -16.4602 variable
7 -64.8768 0.500 1.88300 40.8
8 6.8749 0.805
9 -10.3549 0.500 1.88300 40.8
10 6.3164 0.971 1.94595 18.0
11 62.8936 variable
12 13.8566 0.976 1.61881 63.9
13 -16.0704 0.700
14 infinity variable Aperture stop
15 11.9217 2.188 1.92286 20.9
16 5.6561 3.000 1.65844 50.9
17 -17.6911 variable
18 -15.1485 0.500 1.90366 31.3
19 24.5760 0.400
20 9.8374 2.099 1.72916 54.7
21 -31.4230 0.889
22 28.9853 2.051 1.54470 56.2
23 16.3952 1.429
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 2.351

Various focal lengths at the wide-angle end, intermediate position, and telephoto end (mm) 4.65 10.03 22.08
Fno 3.90 4.40 5.30
ω (degrees) 40.03 21.28 10.03
d6 (mm) 0.460 4.237 7.003
d11 (mm) 6.943 3.166 0.400
d14 (mm) 9.697 5.449 2.027
d17 (mm) 2.308 6.556 9.978

Aspheric coefficients and conic constants of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -9.08101E-05 -6.97333E-07 7.02363E-09 0 0
6 0 1.56134E-04 -1.04162E-06 1.63182E-08 0 0
12 0 -2.58102E-04 -3.20972E-04 7.49112E-05 -8.22276E-06 0
13 0 -2.70404E-05 -3.12399E-04 7.24721E-05 -7.84379E-06 0
22 0 -2.30711E-03 8.75808E-05 -5.16441E-06 1.44180E-07 1.35168E-17
23 0 -2.91979E-03 1.50228E-04 -8.21965E-06 2.06795E-07 1.01981E-12

Other specifications Total lens length (mm) 54.000
Back focus (mm) 4.940
First lens group focal length (mm) 10.978
Second lens group focal length (mm) -4.072
Third lens group focal length (mm) 12.176
4th lens group focal length (mm) 15.066
5th lens group focal length (mm) -122.708
Zoom ratio 4.748
Y '(mm) 3.906

(Example 3)
Table 3 shows lens data of Example 3. FIG. 12 is a cross-sectional view of the image pickup lens of Example 3. The movement of the lens at the time of zooming is schematically shown by arrows. The reference numerals shown in FIG. 12 correspond to the constituent elements in the embodiment of FIG. FIG. 13 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the wide-angle end in Example 3. FIG. 14 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end of the third embodiment. FIG. 15 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 3.

[Table 3] Numerical Example 3
Optical system data
sr (mm) d (mm) nd νd
1 31.0959 0.500 1.92286 20.9
2 15.0173 1.500
3 infinity 9.000 1.94595 18.0
4 infinity 0.200
5 11.3312 2.469 1.69350 53.2
6 -28.0708 variable
7 1164.5834 0.500 1.88300 40.8
8 6.9836 1.236
9 -7.8044 0.500 1.88300 40.8
10 8.5117 0.884 1.94595 18.0
11 74836.3695 variable
12 10.4201 0.938 1.69350 53.2
13 -44.0535 0.400
14 infinity variable Aperture stop
15 13.0551 0.500 1.92286 20.9
16 6.2952 3.000 1.72916 54.7
17 -21.2209 variable
18 -21.8239 0.500 1.90366 31.3
19 9.8060 0.620
20 8.7891 3.329 1.88300 40.8
21 -10.8977 2.112
22 -4.6540 3.000 1.54470 56.2
23 -21.6344 0.400
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 1.200

Each value at the wide-angle end, intermediate position, and telephoto end Focal length (mm) 5.89 12.69 28.49
Fno 3.90 4.32 5.43
ω (degrees) 33.22 16.92 7.71
d6 (mm) 0.460 4.290 7.069
d11 (mm) 7.009 3.178 0.400
d14 (mm) 9.425 5.537 2.000
d17 (mm) 2.645 6.534 10.070

Aspheric coefficients and conic constants of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -8.70341E-05 -7.99389E-07 7.34219E-08 -2.06942E-09 0
6 0 1.92004E-05 7.37493E-07 2.09314E-08 -1.33759E-09 0
12 0 1.99832E-03 4.01860E-05 2.52951E-05 5.42254E-08 0
13 0 2.31250E-03 8.86806E-05 1.87054E-05 1.54399E-06 0
22 0 -3.67568E-03 8.73142E-05 1.64414E-05 -4.67511E-07 1.44112E-17
23 0 -8.68070E-03 4.90312E-04 -1.35021E-05 2.01050E-07 1.62170E-12

Other specifications Lens total length (mm) 53.827
Back focus (mm) 2.759
First lens group focal length (mm) 14.398
Second lens group focal length (mm) -4.043
Third lens group focal length (mm) 12.238
Fourth lens group focal length (mm) 13.929
5th lens group focal length (mm) -46.631
Zoom ratio 4.835
Y '(mm) 3.86

Example 4
Table 4 shows lens data of Example 4. FIG. 16 is a cross-sectional view of the image pickup lens of Example 4. The movement of the lens at the time of zooming is schematically shown by arrows. The reference numerals shown in FIG. 16 correspond to the constituent elements in the embodiment of FIG. FIG. 17 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the wide-angle end in Example 4. FIG. 18 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end of Example 4. FIG. 19 shows aberration diagrams (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 4.

[Table 4] Numerical Example 4
Optical system data
sr (mm) d (mm) nd νd
1 39.8415 0.500 1.92286 20.9
2 17.5800 1.500
3 infinity 9.000 1.94595 18.0
4 infinity 0.571
5 11.8426 2.333 1.72903 54.0
6 -35.1758 variable
7 -1752.4042 0.500 1.88300 40.8
8 7.5346 0.919
9 -8.4546 0.500 1.88300 40.8
10 10.3058 0.858 1.94595 18.0
11 -344.6464 variable
12 138.4000 0.867 1.69350 53.2
13 -10.9570 0.400
14 infinity variable Aperture stop
15 23.6005 0.500 1.94595 18.0
16 11.2504 3.000 1.72916 54.7
17 -18.1995 variable
18 29.7507 0.500 1.90366 31.3
19 9.7650 0.400
20 8.0258 4.000 1.88300 40.8
21 10.4894 0.729
22 6.3848 2.885 1.54470 56.2
23 10.8691 1.642
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 2.442

Each value at the wide-angle end, intermediate position, and telephoto end Focal length (mm) 5.20 11.41 24.69
Fno 3.90 4.32 5.43
ω (degrees) 36.60 18.69 8.89
d6 (mm) 0.460 4.330 6.959
d11 (mm) 6.899 3.030 0.400
d14 (mm) 11.953 6.695 2.000
d17 (mm) 1.359 6.617 11.312

Aspheric coefficients and conic constants of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -4.72770E-05 -7.42021E-07 4.53031E-08 -1.22469E-09 0
6 0 5.08742E-05 -3.30615E-07 2.69544E-08 -9.39580E-10 0
12 0 -8.97538E-04 -2.87789E-04 4.10578E-05 -5.32131E-06 0
13 0 -7.15727E-04 -2.31665E-04 2.82439E-05 -3.62302E-06 0
22 0 -9.79186E-04 -3.49402E-06 -1.85066E-06 7.63976E-09 1.40504E-17
23 0 -1.04477E-03 1.52592E-05 -4.14258E-06 1.08064E-07 1.62171E-12

Other specifications Total lens length (mm) 56.219
Back focus (mm) 5.243
First lens group focal length (mm) 14.809
2nd lens focal length (mm) -4.488
Third lens group focal length (mm) 14.675
Fourth lens group focal length (mm) 16.891
5th lens group focal length (mm) 86.894
Zoom ratio 4.750
Y '(mm) 3.86

(Example 5)
Table 5 shows lens data of Example 5. FIG. 20 is a cross-sectional view of the image pickup lens of Example 5. The movement of the lens at the time of zooming is schematically shown by arrows. The reference numerals shown in FIG. 20 correspond to the reference numerals of components in the embodiment of FIG. FIG. 21 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the wide-angle end in Example 5. FIG. 22 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end of Example 5. FIG. 23 shows aberration diagrams (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 5.

[Table 5] Numerical Example 5
Optical system data
sr (mm) d (mm) nd νd
1 30.2655 0.500 1.92286 20.9
2 15.2488 1.500
3 infinity 9.000 1.92286 20.9
4 infinity 0.281
5 11.3745 2.355 1.72903 54.0
6 -38.9012 variable
7 373.1771 0.500 1.88300 40.8
8 7.2395 0.899
9 -8.2221 1.338 1.88300 40.8
10 12.4077 0.780 1.94595 18.0
11 -161.9376 variable
12 138.3692 0.941 1.55332 71.7
13 -8.1751 0.400
14 infinity variable Aperture stop
15 31.3793 0.500 1.92286 20.9
16 14.1969 3.000 1.72916 54.7
17 -24.5559 variable
18 32.1455 0.500 1.84666 23.8
19 12.8696 0.659
20 11.2965 4.000 1.69680 55.5
21 35.3363 1.411
22 6.6852 3.000 1.54470 56.2
23 7.4036 1.641
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 2.441

Each value at the wide-angle end, intermediate position, and telephoto end Focal length (mm) 5.75 12.50 27.33
Fno 3.90 4.32 5.43
ω (degrees) 33.85 17.16 8.04
d6 (mm) 0.460 4.341 6.848
d11 (mm) 6.788 2.907 0.400
d14 (mm) 17.581 9.242 2.000
d17 (mm) 1.383 9.722 16.964

Aspheric coefficients and conic constants of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -6.28320E-05 -7.22612E-07 3.69214E-08 -1.47401E-09 0
6 0 2.33812E-05 5.73872E-08 6.10641E-09 -8.93051E-10 0
12 0 -1.62978E-03 -3.71485E-04 4.58414E-05 -8.97556E-06 0
13 0 -1.27566E-03 -2.91119E-04 2.72798E-05 -5.70376E-06 0
22 0 -5.81788E-04 -9.92105E-06 -1.93633E-07 -1.10745E-08 -1.75316E-10
23 0 -1.48317E-03 -3.08702E-06 -2.06859E-06 4.06214E-08 8.35365E-11

Other specifications Total lens length (mm) 63.359
Back focus (mm) 5.241
First lens group focal length (mm) 14.867
Second lens group focal length (mm) -4.466
Third lens group focal length (mm) 13.982
Fourth lens group focal length (mm) 22.462
5th lens group focal length (mm) 41.246
Zoom ratio 4.750
Y '(mm) 3.86

(Example 6)
Table 6 shows lens data of Example 6. FIG. 24 is a cross-sectional view of the image pickup lens of Example 6. The movement of the lens during zooming is schematically shown by arrows. The reference numerals shown in FIG. 24 correspond to the reference numerals of the components in the embodiment of FIG. FIG. 25 shows aberration diagrams (spherical aberration (a), astigmatism (b), distortion aberration (c)) at the wide-angle end in Example 6. FIG. 26 is an aberration diagram (spherical aberration (a), astigmatism (b), distortion (c)) at the intermediate end in Example 6. FIG. 27 shows aberration diagrams (spherical aberration (a), astigmatism (b), distortion (c)) at the telephoto end of Example 6.

[Table 6] Numerical Example 6
Optical system data
sr (mm) d (mm) nd νd
1 156.3469 0.500 1.92286 20.9
2 14.9947 1.500
3 infinity 9.000 1.75211 25.0
4 infinity 0.643
5 11.5865 2.363 1.75501 51.2
6 -20.6808 variable
7 294.7267 0.500 1.88300 40.8
8 6.3033 0.897
9 -9.1005 0.500 1.88300 40.8
10 7.6935 0.906 1.94595 18.0
11 113.2348 variable
12 13.6988 0.983 1.62263 58.2
13 -14.7642 0.400
14 infinity variable Aperture stop
15 13.8646 0.500 1.92286 20.9
16 6.5990 3.000 1.65844 50.9
17 -17.7628 variable
18 -12.2472 0.500 1.90366 31.3
19 26.0691 0.400
20 9.9520 3.938 1.72916 54.7
21 -25.5039 0.400
22 6.1045 2.770 1.54470 56.2
23 5.8889 1.270
24 infinity 0.500 1.51633 64.1
25 infinity 0.500
26 infinity 0.500 1.51633 64.1
27 infinity 1.229

Each value focal length at the wide-angle end, intermediate position, and telephoto end (mm) 4.31 9.51 20.49
Fno 3.90 4.40 5.30
ω (degrees) 41.83 22.10 10.67
d6 (mm) 0.460 4.367 7.043
d11 (mm) 6.983 3.076 0.400
d14 (mm) 10.513 5.614 2.000
d17 (mm) 2.532 7.430 11.044

Aspheric coefficients and conic constants of aspheric lenses
s K A4 A6 A8 A10 A12
5 0 -6.89869E-05 -1.23346E-07 -9.02786E-09 0 0
6 0 1.27422E-04 -7.91793E-07 2.28444E-09 0 0
12 0 -2.24634E-04 -1.80754E-04 1.90232E-05 -2.45220E-06 0
13 0 -2.85536E-06 -1.62321E-04 1.68248E-05 -2.29192E-06 0
22 0 -5.47833E-04 -7.92123E-06 -4.67442E-07 -4.39795E-08 1.31060E-17
23 0 -3.56325E-04 5.49146E-05 -6.05794E-06 -8.90381E-09 1.01981E-12

Other specifications Total lens length (mm) 54.187
Back focus (mm) 3.658
First lens group focal length (mm) 11.721
Second lens group focal length (mm) -4.049
3rd lens group focal length (mm) 11.566
Fourth lens group focal length (mm) 16.184
5th lens group focal length (mm) 69.125
Zoom ratio 4.750
Y '(mm) 3.86

  Table 7 shows values of the examples corresponding to the respective conditional expressions.

  It should be noted that the present invention is not limited to the examples described in the specification, and that other examples and modifications are included in the present field from the examples and technical ideas described in the present specification. It will be apparent to those skilled in the art. For example, even when a dummy lens group having substantially no refractive power is further added, it is within the scope of the present invention.

DESCRIPTION OF SYMBOLS 10 Image pick-up device 12 Case 12a Opening 14 Cover member 32 Display 34 Release button 36 Power switch 38 Zoom operation switch 40 Operation switch 42 Protection plate 50 Lens barrel 60 Shutter mechanism CG Cover glass G1-G11 Lens GR1-GR5 Lens group IM Solid imaging Element LP Low-pass filter MR Reflective member ZL Zoom lens

Claims (11)

From the object side,
A first lens unit having a positive refractive power that is fixed at the time of zooming;
A second lens group having a negative refractive power that moves along the optical axis at the time of zooming;
A third lens group having a positive refractive power which is fixed at the time of zooming;
A fourth lens group having a positive refractive power that moves along the optical axis upon zooming;
Consists of a fifth lens group fixed at the time of zooming,
The first lens group has a reflecting member for bending the optical axis,
The fourth lens group is composed of a cemented lens in which a negative lens and a positive lens are bonded together in order from the object side,
The fifth lens group includes a first negative lens having negative refractive power, a second positive lens having positive refractive power, and a third lens in order from the object side.
The second positive lens of the fifth lens group is shifted in a direction perpendicular to the optical axis to correct image blur, and the focal length of the second positive lens of the fifth lens group is fs (mm). A zoom lens characterized in that the following conditional expression is satisfied, where the focal length at the telephoto end is ft (mm).
0.2 <fs / ft <0.9 (1) The distance that the second lens group moves by zooming from the wide-angle end to the telephoto end is d2 (mm), and the distance that the fourth lens group moves by zooming from the wide-angle end to the telephoto end is d4 (mm). The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
0.4 <d2 / d4 <0.9 (2)   The zoom lens according to claim 1, wherein the second lens group includes three or less lenses. The following conditional expressions are satisfied, where βs is a lateral magnification of the second positive lens of the fifth lens group, and βp is a lateral magnification of the third lens of the fifth lens group. 4. The zoom lens according to any one of items 3.
0.5 <(1-βs) × βp <1.6 (3)   5. The zoom lens according to claim 1, wherein the third lens of the fifth lens group is made of plastic. 6. 6. The zoom lens according to claim 5, wherein the following conditional expression is satisfied, where a focal length of the third lens of the fifth lens group is fp (mm).
0.3 <| fp / ft | (4) The focal length at the wide-angle end of the entire system is fw (mm), and the distance on the optical axis from the object-side vertex of the first lens of the first lens group to the reflecting surface of the reflecting member is d _L1PR (mm). The zoom lens according to claim 1, wherein the following conditional expression is satisfied.
1.0 < _dL1PR / fw <1.6 (5)   The zoom lens according to claim 1, wherein an aperture stop is located between the third lens group and the fourth lens group. A zoom lens for forming a subject image on an imaging surface having a diagonal length of 2Y ′ (mm) of a solid-state imaging device, where the focal length at the wide-angle end of the entire system is fw (mm), and the following conditional expression The zoom lens according to claim 1, wherein the zoom lens satisfies the following.
1.3 <2Y ′ / fw <1.8 (6)   The zoom lens according to claim 1, further comprising a lens group having substantially no refractive power.   An imaging apparatus comprising the zoom lens according to claim 1.

Images